diff --git a/packages/bazel/src/ng_module.bzl b/packages/bazel/src/ng_module.bzl
index fceadb3a7d..68d008a980 100644
--- a/packages/bazel/src/ng_module.bzl
+++ b/packages/bazel/src/ng_module.bzl
@@ -71,6 +71,7 @@ def _ngc_tsconfig(ctx, files, srcs, **kwargs):
       "angularCompilerOptions": {
           "generateCodeForLibraries": False,
           "allowEmptyCodegenFiles": True,
+          "enableSummariesforJit": True,
           # FIXME: wrong place to de-dupe
           "expectedOut": depset([o.path for o in expected_outs]).to_list()
       }
diff --git a/packages/compiler-cli/integrationtest/tsconfig-xi18n.json b/packages/compiler-cli/integrationtest/tsconfig-xi18n.json
index 50af710615..b99e0f28b5 100644
--- a/packages/compiler-cli/integrationtest/tsconfig-xi18n.json
+++ b/packages/compiler-cli/integrationtest/tsconfig-xi18n.json
@@ -3,7 +3,8 @@
     // For TypeScript 1.8, we have to lay out generated files
     // in the same source directory with your code.
     "genDir": ".",
-    "debug": true
+    "debug": true,
+    "enableSummariesForJit": true
   },
 
   "compilerOptions": {
diff --git a/packages/compiler-cli/src/main.ts b/packages/compiler-cli/src/main.ts
index 626904b7b8..b34cf29596 100644
--- a/packages/compiler-cli/src/main.ts
+++ b/packages/compiler-cli/src/main.ts
@@ -18,7 +18,7 @@ import * as api from './transformers/api';
 import * as ngc from './transformers/entry_points';
 import {GENERATED_FILES} from './transformers/util';
 
-import {exitCodeFromResult, performCompilation, readConfiguration, formatDiagnostics, Diagnostics, ParsedConfiguration, PerformCompilationResult} from './perform_compile';
+import {exitCodeFromResult, performCompilation, readConfiguration, formatDiagnostics, Diagnostics, ParsedConfiguration, PerformCompilationResult, filterErrorsAndWarnings} from './perform_compile';
 import {performWatchCompilation, createPerformWatchHost} from './perform_watch';
 import {isSyntaxError} from '@angular/compiler';
 
@@ -130,8 +130,9 @@ export function readCommandLineAndConfiguration(
 function reportErrorsAndExit(
     options: api.CompilerOptions, allDiagnostics: Diagnostics,
     consoleError: (s: string) => void = console.error): number {
-  if (allDiagnostics.length) {
-    consoleError(formatDiagnostics(options, allDiagnostics));
+  const errorsAndWarnings = filterErrorsAndWarnings(allDiagnostics);
+  if (errorsAndWarnings.length) {
+    consoleError(formatDiagnostics(options, errorsAndWarnings));
   }
   return exitCodeFromResult(allDiagnostics);
 }
diff --git a/packages/compiler-cli/src/ngtools_api2.ts b/packages/compiler-cli/src/ngtools_api2.ts
index 9c0ab6584b..d4c1c0ab2f 100644
--- a/packages/compiler-cli/src/ngtools_api2.ts
+++ b/packages/compiler-cli/src/ngtools_api2.ts
@@ -19,9 +19,11 @@ import {ParseSourceSpan} from '@angular/compiler';
 import * as ts from 'typescript';
 
 import {formatDiagnostics as formatDiagnosticsOrig} from './perform_compile';
+import {Program as ProgramOrig} from './transformers/api';
 import {createCompilerHost as createCompilerOrig} from './transformers/compiler_host';
 import {createProgram as createProgramOrig} from './transformers/program';
 
+
 // Interfaces from ./transformers/api;
 export interface Diagnostic {
   messageText: string;
@@ -92,12 +94,6 @@ export interface TsEmitArguments {
 
 export interface TsEmitCallback { (args: TsEmitArguments): ts.EmitResult; }
 
-export interface LibrarySummary {
-  fileName: string;
-  text: string;
-  sourceFile?: ts.SourceFile;
-}
-
 export interface Program {
   getTsProgram(): ts.Program;
   getTsOptionDiagnostics(cancellationToken?: ts.CancellationToken): ts.Diagnostic[];
@@ -116,7 +112,6 @@ export interface Program {
     customTransformers?: CustomTransformers,
     emitCallback?: TsEmitCallback
   }): ts.EmitResult;
-  getLibrarySummaries(): LibrarySummary[];
 }
 
 // Wrapper for createProgram.
@@ -124,7 +119,7 @@ export function createProgram(
     {rootNames, options, host, oldProgram}:
         {rootNames: string[], options: CompilerOptions, host: CompilerHost, oldProgram?: Program}):
     Program {
-  return createProgramOrig({rootNames, options, host, oldProgram});
+  return createProgramOrig({rootNames, options, host, oldProgram: oldProgram as ProgramOrig});
 }
 
 // Wrapper for createCompilerHost.
diff --git a/packages/compiler-cli/src/perform_compile.ts b/packages/compiler-cli/src/perform_compile.ts
index 18fc69b9eb..0bfcf98fbb 100644
--- a/packages/compiler-cli/src/perform_compile.ts
+++ b/packages/compiler-cli/src/perform_compile.ts
@@ -13,11 +13,16 @@ import * as ts from 'typescript';
 
 import * as api from './transformers/api';
 import * as ng from './transformers/entry_points';
+import {createMessageDiagnostic} from './transformers/util';
 
 const TS_EXT = /\.ts$/;
 
 export type Diagnostics = Array<ts.Diagnostic|api.Diagnostic>;
 
+export function filterErrorsAndWarnings(diagnostics: Diagnostics): Diagnostics {
+  return diagnostics.filter(d => d.category !== ts.DiagnosticCategory.Message);
+}
+
 export function formatDiagnostics(options: api.CompilerOptions, diags: Diagnostics): string {
   if (diags && diags.length) {
     const tsFormatHost: ts.FormatDiagnosticsHost = {
@@ -123,7 +128,7 @@ export interface PerformCompilationResult {
 }
 
 export function exitCodeFromResult(diags: Diagnostics | undefined): number {
-  if (!diags || diags.length === 0) {
+  if (!diags || filterErrorsAndWarnings(diags).length === 0) {
     // If we have a result and didn't get any errors, we succeeded.
     return 0;
   }
@@ -154,7 +159,13 @@ export function performCompilation({rootNames, options, host, oldProgram, emitCa
 
     program = ng.createProgram({rootNames, host, options, oldProgram});
 
+    const beforeDiags = Date.now();
     allDiagnostics.push(...gatherDiagnostics(program !));
+    if (options.diagnostics) {
+      const afterDiags = Date.now();
+      allDiagnostics.push(
+          createMessageDiagnostic(`Time for diagnostics: ${afterDiags - beforeDiags}ms.`));
+    }
 
     if (!hasErrors(allDiagnostics)) {
       emitResult = program !.emit({emitCallback, customTransformers, emitFlags});
diff --git a/packages/compiler-cli/src/perform_watch.ts b/packages/compiler-cli/src/perform_watch.ts
index c83ae86b21..c5acc570f0 100644
--- a/packages/compiler-cli/src/perform_watch.ts
+++ b/packages/compiler-cli/src/perform_watch.ts
@@ -13,27 +13,7 @@ import * as ts from 'typescript';
 import {Diagnostics, ParsedConfiguration, PerformCompilationResult, exitCodeFromResult, performCompilation, readConfiguration} from './perform_compile';
 import * as api from './transformers/api';
 import {createCompilerHost} from './transformers/entry_points';
-
-const ChangeDiagnostics = {
-  Compilation_complete_Watching_for_file_changes: {
-    category: ts.DiagnosticCategory.Message,
-    messageText: 'Compilation complete. Watching for file changes.',
-    code: api.DEFAULT_ERROR_CODE,
-    source: api.SOURCE
-  },
-  Compilation_failed_Watching_for_file_changes: {
-    category: ts.DiagnosticCategory.Message,
-    messageText: 'Compilation failed. Watching for file changes.',
-    code: api.DEFAULT_ERROR_CODE,
-    source: api.SOURCE
-  },
-  File_change_detected_Starting_incremental_compilation: {
-    category: ts.DiagnosticCategory.Message,
-    messageText: 'File change detected. Starting incremental compilation.',
-    code: api.DEFAULT_ERROR_CODE,
-    source: api.SOURCE
-  },
-};
+import {createMessageDiagnostic} from './transformers/util';
 
 function totalCompilationTimeDiagnostic(timeInMillis: number): api.Diagnostic {
   let duration: string;
@@ -231,9 +211,11 @@ export function performWatchCompilation(host: PerformWatchHost):
     const exitCode = exitCodeFromResult(compileResult.diagnostics);
     if (exitCode == 0) {
       cachedProgram = compileResult.program;
-      host.reportDiagnostics([ChangeDiagnostics.Compilation_complete_Watching_for_file_changes]);
+      host.reportDiagnostics(
+          [createMessageDiagnostic('Compilation complete. Watching for file changes.')]);
     } else {
-      host.reportDiagnostics([ChangeDiagnostics.Compilation_failed_Watching_for_file_changes]);
+      host.reportDiagnostics(
+          [createMessageDiagnostic('Compilation failed. Watching for file changes.')]);
     }
 
     return compileResult.diagnostics;
@@ -285,7 +267,7 @@ export function performWatchCompilation(host: PerformWatchHost):
   function recompile() {
     timerHandleForRecompilation = undefined;
     host.reportDiagnostics(
-        [ChangeDiagnostics.File_change_detected_Starting_incremental_compilation]);
+        [createMessageDiagnostic('File change detected. Starting incremental compilation.')]);
     doCompilation();
   }
 }
\ No newline at end of file
diff --git a/packages/compiler-cli/src/transformers/api.ts b/packages/compiler-cli/src/transformers/api.ts
index 7829f956f0..d5aff54dc9 100644
--- a/packages/compiler-cli/src/transformers/api.ts
+++ b/packages/compiler-cli/src/transformers/api.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {ParseSourceSpan} from '@angular/compiler';
+import {GeneratedFile, ParseSourceSpan} from '@angular/compiler';
 import * as ts from 'typescript';
 
 export const DEFAULT_ERROR_CODE = 100;
@@ -144,6 +144,12 @@ export interface CompilerOptions extends ts.CompilerOptions {
 
   /** generate all possible generated files  */
   allowEmptyCodegenFiles?: boolean;
+
+  /**
+   * Whether to generate .ngsummary.ts files that allow to use AOTed artifacts
+   * in JIT mode. This is off by default.
+   */
+  enableSummariesForJit?: boolean;
 }
 
 export interface CompilerHost extends ts.CompilerHost {
@@ -214,6 +220,9 @@ export interface TsEmitArguments {
 
 export interface TsEmitCallback { (args: TsEmitArguments): ts.EmitResult; }
 
+/**
+ * @internal
+ */
 export interface LibrarySummary {
   fileName: string;
   text: string;
@@ -300,6 +309,13 @@ export interface Program {
    * Returns the .d.ts / .ngsummary.json / .ngfactory.d.ts files of libraries that have been emitted
    * in this program or previous programs with paths that emulate the fact that these libraries
    * have been compiled before with no outDir.
+   *
+   * @internal
    */
-  getLibrarySummaries(): LibrarySummary[];
+  getLibrarySummaries(): Map<string, LibrarySummary>;
+
+  /**
+   * @internal
+   */
+  getEmittedGeneratedFiles(): Map<string, GeneratedFile>;
 }
diff --git a/packages/compiler-cli/src/transformers/compiler_host.ts b/packages/compiler-cli/src/transformers/compiler_host.ts
index 85e7702f4c..acdf9f5c0d 100644
--- a/packages/compiler-cli/src/transformers/compiler_host.ts
+++ b/packages/compiler-cli/src/transformers/compiler_host.ts
@@ -58,7 +58,6 @@ export class TsCompilerAotCompilerTypeCheckHostAdapter extends
   private generatedSourceFiles = new Map<string, GenSourceFile>();
   private generatedCodeFor = new Map<string, string[]>();
   private emitter = new TypeScriptEmitter();
-  private librarySummaries = new Map<string, LibrarySummary>();
   getCancellationToken: () => ts.CancellationToken;
   getDefaultLibLocation: () => string;
   trace: (s: string) => void;
@@ -68,9 +67,8 @@ export class TsCompilerAotCompilerTypeCheckHostAdapter extends
   constructor(
       private rootFiles: string[], options: CompilerOptions, context: CompilerHost,
       private metadataProvider: MetadataProvider, private codeGenerator: CodeGenerator,
-      librarySummaries: LibrarySummary[]) {
+      private librarySummaries = new Map<string, LibrarySummary>()) {
     super(options, context);
-    librarySummaries.forEach(summary => this.librarySummaries.set(summary.fileName, summary));
     this.moduleResolutionCache = ts.createModuleResolutionCache(
         this.context.getCurrentDirectory !(), this.context.getCanonicalFileName.bind(this.context));
     const basePath = this.options.basePath !;
diff --git a/packages/compiler-cli/src/transformers/node_emitter_transform.ts b/packages/compiler-cli/src/transformers/node_emitter_transform.ts
index 47b9354ade..0153e90848 100644
--- a/packages/compiler-cli/src/transformers/node_emitter_transform.ts
+++ b/packages/compiler-cli/src/transformers/node_emitter_transform.ts
@@ -10,6 +10,7 @@ import {GeneratedFile} from '@angular/compiler';
 import * as ts from 'typescript';
 
 import {TypeScriptNodeEmitter} from './node_emitter';
+import {GENERATED_FILES} from './util';
 
 const PREAMBLE = `/**
 * @fileoverview This file is generated by the Angular template compiler.
@@ -18,17 +19,17 @@ const PREAMBLE = `/**
 * tslint:disable
 */`;
 
-export function getAngularEmitterTransformFactory(generatedFiles: GeneratedFile[]): () =>
+export function getAngularEmitterTransformFactory(generatedFiles: Map<string, GeneratedFile>): () =>
     (sourceFile: ts.SourceFile) => ts.SourceFile {
   return function() {
-    const map = new Map(generatedFiles.filter(g => g.stmts && g.stmts.length)
-                            .map<[string, GeneratedFile]>(g => [g.genFileUrl, g]));
     const emitter = new TypeScriptNodeEmitter();
     return function(sourceFile: ts.SourceFile): ts.SourceFile {
-      const g = map.get(sourceFile.fileName);
+      const g = generatedFiles.get(sourceFile.fileName);
       if (g && g.stmts) {
         const [newSourceFile] = emitter.updateSourceFile(sourceFile, g.stmts, PREAMBLE);
         return newSourceFile;
+      } else if (GENERATED_FILES.test(sourceFile.fileName)) {
+        return ts.updateSourceFileNode(sourceFile, []);
       }
       return sourceFile;
     };
diff --git a/packages/compiler-cli/src/transformers/program.ts b/packages/compiler-cli/src/transformers/program.ts
index e24c4209ae..205a4f40f7 100644
--- a/packages/compiler-cli/src/transformers/program.ts
+++ b/packages/compiler-cli/src/transformers/program.ts
@@ -18,7 +18,13 @@ import {CompilerHost, CompilerOptions, CustomTransformers, DEFAULT_ERROR_CODE, D
 import {CodeGenerator, TsCompilerAotCompilerTypeCheckHostAdapter, getOriginalReferences} from './compiler_host';
 import {LowerMetadataCache, getExpressionLoweringTransformFactory} from './lower_expressions';
 import {getAngularEmitterTransformFactory} from './node_emitter_transform';
-import {GENERATED_FILES, StructureIsReused, tsStructureIsReused} from './util';
+import {GENERATED_FILES, StructureIsReused, createMessageDiagnostic, tsStructureIsReused} from './util';
+
+/**
+ * Maximum number of files that are emitable via calling ts.Program.emit
+ * passing individual targetSourceFiles.
+ */
+const MAX_FILE_COUNT_FOR_SINGLE_FILE_EMIT = 20;
 
 const emptyModules: NgAnalyzedModules = {
   ngModules: [],
@@ -32,18 +38,20 @@ const defaultEmitCallback: TsEmitCallback =
         program.emit(
             targetSourceFile, writeFile, cancellationToken, emitOnlyDtsFiles, customTransformers);
 
-
 class AngularCompilerProgram implements Program {
   private metadataCache: LowerMetadataCache;
-  private oldProgramLibrarySummaries: LibrarySummary[] = [];
+  private oldProgramLibrarySummaries: Map<string, LibrarySummary>|undefined;
+  private oldProgramEmittedGeneratedFiles: Map<string, GeneratedFile>|undefined;
   // Note: This will be cleared out as soon as we create the _tsProgram
   private oldTsProgram: ts.Program|undefined;
   private emittedLibrarySummaries: LibrarySummary[]|undefined;
+  private emittedGeneratedFiles: GeneratedFile[]|undefined;
 
   // Lazily initialized fields
   private _typeCheckHost: TypeCheckHost;
   private _compiler: AotCompiler;
   private _tsProgram: ts.Program;
+  private _changedNonGenFileNames: string[]|undefined;
   private _analyzedModules: NgAnalyzedModules|undefined;
   private _structuralDiagnostics: Diagnostic[]|undefined;
   private _programWithStubs: ts.Program|undefined;
@@ -60,6 +68,7 @@ class AngularCompilerProgram implements Program {
     this.oldTsProgram = oldProgram ? oldProgram.getTsProgram() : undefined;
     if (oldProgram) {
       this.oldProgramLibrarySummaries = oldProgram.getLibrarySummaries();
+      this.oldProgramEmittedGeneratedFiles = oldProgram.getEmittedGeneratedFiles();
     }
 
     if (options.flatModuleOutFile) {
@@ -81,10 +90,26 @@ class AngularCompilerProgram implements Program {
     this.metadataCache = new LowerMetadataCache({quotedNames: true}, !!options.strictMetadataEmit);
   }
 
-  getLibrarySummaries(): LibrarySummary[] {
-    const result = [...this.oldProgramLibrarySummaries];
+  getLibrarySummaries(): Map<string, LibrarySummary> {
+    const result = new Map<string, LibrarySummary>();
+    if (this.oldProgramLibrarySummaries) {
+      this.oldProgramLibrarySummaries.forEach((summary, fileName) => result.set(fileName, summary));
+    }
     if (this.emittedLibrarySummaries) {
-      result.push(...this.emittedLibrarySummaries);
+      this.emittedLibrarySummaries.forEach(
+          (summary, fileName) => result.set(summary.fileName, summary));
+    }
+    return result;
+  }
+
+  getEmittedGeneratedFiles(): Map<string, GeneratedFile> {
+    const result = new Map<string, GeneratedFile>();
+    if (this.oldProgramEmittedGeneratedFiles) {
+      this.oldProgramEmittedGeneratedFiles.forEach(
+          (genFile, fileName) => result.set(fileName, genFile));
+    }
+    if (this.emittedGeneratedFiles) {
+      this.emittedGeneratedFiles.forEach((genFile) => result.set(genFile.genFileUrl, genFile));
     }
     return result;
   }
@@ -142,6 +167,7 @@ class AngularCompilerProgram implements Program {
         customTransformers?: CustomTransformers,
         emitCallback?: TsEmitCallback
       } = {}): ts.EmitResult {
+    const emitStart = Date.now();
     if (emitFlags & EmitFlags.I18nBundle) {
       const locale = this.options.i18nOutLocale || null;
       const file = this.options.i18nOutFile || null;
@@ -153,7 +179,7 @@ class AngularCompilerProgram implements Program {
         0) {
       return {emitSkipped: true, diagnostics: [], emittedFiles: []};
     }
-    const {genFiles, genDiags} = this.generateFilesForEmit(emitFlags);
+    let {genFiles, genDiags} = this.generateFilesForEmit(emitFlags);
     if (genDiags.length) {
       return {
         diagnostics: genDiags,
@@ -161,11 +187,11 @@ class AngularCompilerProgram implements Program {
         emittedFiles: [],
       };
     }
-    const emittedLibrarySummaries = this.emittedLibrarySummaries = [];
-
+    this.emittedGeneratedFiles = genFiles;
     const outSrcMapping: Array<{sourceFile: ts.SourceFile, outFileName: string}> = [];
     const genFileByFileName = new Map<string, GeneratedFile>();
     genFiles.forEach(genFile => genFileByFileName.set(genFile.genFileUrl, genFile));
+    this.emittedLibrarySummaries = [];
     const writeTsFile: ts.WriteFileCallback =
         (outFileName, outData, writeByteOrderMark, onError?, sourceFiles?) => {
           const sourceFile = sourceFiles && sourceFiles.length == 1 ? sourceFiles[0] : null;
@@ -176,7 +202,8 @@ class AngularCompilerProgram implements Program {
           }
           this.writeFile(outFileName, outData, writeByteOrderMark, onError, genFile, sourceFiles);
         };
-
+    const tsCustomTansformers = this.calculateTransforms(genFileByFileName, customTransformers);
+    const emitOnlyDtsFiles = (emitFlags & (EmitFlags.DTS | EmitFlags.JS)) == EmitFlags.DTS;
     // Restore the original references before we emit so TypeScript doesn't emit
     // a reference to the .d.ts file.
     const augmentedReferences = new Map<ts.SourceFile, ts.FileReference[]>();
@@ -187,16 +214,44 @@ class AngularCompilerProgram implements Program {
         sourceFile.referencedFiles = originalReferences;
       }
     }
+    const genTsFiles: GeneratedFile[] = [];
+    const genJsonFiles: GeneratedFile[] = [];
+    genFiles.forEach(gf => {
+      if (gf.stmts) {
+        genTsFiles.push(gf);
+      }
+      if (gf.source) {
+        genJsonFiles.push(gf);
+      }
+    });
     let emitResult: ts.EmitResult;
+    let emittedUserTsCount: number;
     try {
-      emitResult = emitCallback({
-        program: this.tsProgram,
-        host: this.host,
-        options: this.options,
-        writeFile: writeTsFile,
-        emitOnlyDtsFiles: (emitFlags & (EmitFlags.DTS | EmitFlags.JS)) == EmitFlags.DTS,
-        customTransformers: this.calculateTransforms(genFiles, customTransformers)
-      });
+      const emitChangedFilesOnly = this._changedNonGenFileNames &&
+          this._changedNonGenFileNames.length < MAX_FILE_COUNT_FOR_SINGLE_FILE_EMIT;
+      if (emitChangedFilesOnly) {
+        const fileNamesToEmit =
+            [...this._changedNonGenFileNames !, ...genTsFiles.map(gf => gf.genFileUrl)];
+        emitResult = mergeEmitResults(
+            fileNamesToEmit.map((fileName) => emitResult = emitCallback({
+                                  program: this.tsProgram,
+                                  host: this.host,
+                                  options: this.options,
+                                  writeFile: writeTsFile, emitOnlyDtsFiles,
+                                  customTransformers: tsCustomTansformers,
+                                  targetSourceFile: this.tsProgram.getSourceFile(fileName),
+                                })));
+        emittedUserTsCount = this._changedNonGenFileNames !.length;
+      } else {
+        emitResult = emitCallback({
+          program: this.tsProgram,
+          host: this.host,
+          options: this.options,
+          writeFile: writeTsFile, emitOnlyDtsFiles,
+          customTransformers: tsCustomTansformers
+        });
+        emittedUserTsCount = this.tsProgram.getSourceFiles().length - genTsFiles.length;
+      }
     } finally {
       // Restore the references back to the augmented value to ensure that the
       // checks that TypeScript makes for project structure reuse will succeed.
@@ -207,10 +262,10 @@ class AngularCompilerProgram implements Program {
 
     if (!outSrcMapping.length) {
       // if no files were emitted by TypeScript, also don't emit .json files
+      emitResult.diagnostics.push(createMessageDiagnostic(`Emitted no files.`));
       return emitResult;
     }
 
-
     let sampleSrcFileName: string|undefined;
     let sampleOutFileName: string|undefined;
     if (outSrcMapping.length) {
@@ -220,16 +275,16 @@ class AngularCompilerProgram implements Program {
     const srcToOutPath =
         createSrcToOutPathMapper(this.options.outDir, sampleSrcFileName, sampleOutFileName);
     if (emitFlags & EmitFlags.Codegen) {
-      genFiles.forEach(gf => {
-        if (gf.source) {
-          const outFileName = srcToOutPath(gf.genFileUrl);
-          this.writeFile(outFileName, gf.source, false, undefined, gf);
-        }
+      genJsonFiles.forEach(gf => {
+        const outFileName = srcToOutPath(gf.genFileUrl);
+        this.writeFile(outFileName, gf.source !, false, undefined, gf);
       });
     }
+    let metadataJsonCount = 0;
     if (emitFlags & EmitFlags.Metadata) {
       this.tsProgram.getSourceFiles().forEach(sf => {
         if (!sf.isDeclarationFile && !GENERATED_FILES.test(sf.fileName)) {
+          metadataJsonCount++;
           const metadata = this.metadataCache.getMetadata(sf);
           const metadataText = JSON.stringify([metadata]);
           const outFileName = srcToOutPath(sf.fileName.replace(/\.ts$/, '.metadata.json'));
@@ -237,6 +292,15 @@ class AngularCompilerProgram implements Program {
         }
       });
     }
+    const emitEnd = Date.now();
+    if (this.options.diagnostics) {
+      emitResult.diagnostics.push(createMessageDiagnostic([
+        `Emitted in ${emitEnd - emitStart}ms`,
+        `- ${emittedUserTsCount} user ts files`,
+        `- ${genTsFiles.length} generated ts files`,
+        `- ${genJsonFiles.length + metadataJsonCount} generated json files`,
+      ].join('\n')));
+    }
     return emitResult;
   }
 
@@ -281,8 +345,9 @@ class AngularCompilerProgram implements Program {
         (this._semanticDiagnostics = this.generateSemanticDiagnostics());
   }
 
-  private calculateTransforms(genFiles: GeneratedFile[], customTransformers?: CustomTransformers):
-      ts.CustomTransformers {
+  private calculateTransforms(
+      genFiles: Map<string, GeneratedFile>,
+      customTransformers?: CustomTransformers): ts.CustomTransformers {
     const beforeTs: ts.TransformerFactory<ts.SourceFile>[] = [];
     if (!this.options.disableExpressionLowering) {
       beforeTs.push(getExpressionLoweringTransformFactory(this.metadataCache));
@@ -353,6 +418,16 @@ class AngularCompilerProgram implements Program {
         sourceFiles.push(sf.fileName);
       }
     });
+    if (oldTsProgram) {
+      // TODO(tbosch): if one of the files contains a `const enum`
+      // always emit all files!
+      const changedNonGenFileNames = this._changedNonGenFileNames = [] as string[];
+      tmpProgram.getSourceFiles().forEach(sf => {
+        if (!GENERATED_FILES.test(sf.fileName) && oldTsProgram.getSourceFile(sf.fileName) !== sf) {
+          changedNonGenFileNames.push(sf.fileName);
+        }
+      });
+    }
     return {tmpProgram, sourceFiles, hostAdapter, rootNames};
   }
 
@@ -418,7 +493,14 @@ class AngularCompilerProgram implements Program {
       if (!(emitFlags & EmitFlags.Codegen)) {
         return {genFiles: [], genDiags: []};
       }
-      const genFiles = this.compiler.emitAllImpls(this.analyzedModules);
+      let genFiles = this.compiler.emitAllImpls(this.analyzedModules);
+      if (this.oldProgramEmittedGeneratedFiles) {
+        const oldProgramEmittedGeneratedFiles = this.oldProgramEmittedGeneratedFiles;
+        genFiles = genFiles.filter(genFile => {
+          const oldGenFile = oldProgramEmittedGeneratedFiles.get(genFile.genFileUrl);
+          return !oldGenFile || !genFile.isEquivalent(oldGenFile);
+        });
+      }
       return {genFiles, genDiags: []};
     } catch (e) {
       // TODO(tbosch): check whether we can actually have syntax errors here,
@@ -533,7 +615,7 @@ function getAotCompilerOptions(options: CompilerOptions): AotCompilerOptions {
     locale: options.i18nInLocale,
     i18nFormat: options.i18nInFormat || options.i18nOutFormat, translations, missingTranslation,
     enableLegacyTemplate: options.enableLegacyTemplate,
-    enableSummariesForJit: true,
+    enableSummariesForJit: options.enableSummariesForJit,
     preserveWhitespaces: options.preserveWhitespaces,
     fullTemplateTypeCheck: options.fullTemplateTypeCheck,
     allowEmptyCodegenFiles: options.allowEmptyCodegenFiles,
@@ -649,3 +731,15 @@ export function i18nGetExtension(formatName: string): string {
 
   throw new Error(`Unsupported format "${formatName}"`);
 }
+
+function mergeEmitResults(emitResults: ts.EmitResult[]): ts.EmitResult {
+  const diagnostics: ts.Diagnostic[] = [];
+  let emitSkipped = true;
+  const emittedFiles: string[] = [];
+  for (const er of emitResults) {
+    diagnostics.push(...er.diagnostics);
+    emitSkipped = emitSkipped || er.emitSkipped;
+    emittedFiles.push(...er.emittedFiles);
+  }
+  return {diagnostics, emitSkipped, emittedFiles};
+}
diff --git a/packages/compiler-cli/src/transformers/util.ts b/packages/compiler-cli/src/transformers/util.ts
index bd2b78b71c..ec774fcde3 100644
--- a/packages/compiler-cli/src/transformers/util.ts
+++ b/packages/compiler-cli/src/transformers/util.ts
@@ -8,6 +8,8 @@
 
 import * as ts from 'typescript';
 
+import {DEFAULT_ERROR_CODE, Diagnostic, SOURCE} from './api';
+
 export const GENERATED_FILES = /(.*?)\.(ngfactory|shim\.ngstyle|ngstyle|ngsummary)\.(js|d\.ts|ts)$/;
 
 export const enum StructureIsReused {Not = 0, SafeModules = 1, Completely = 2}
@@ -15,4 +17,15 @@ export const enum StructureIsReused {Not = 0, SafeModules = 1, Completely = 2}
 // Note: This is an internal property in TypeScript. Use it only for assertions and tests.
 export function tsStructureIsReused(program: ts.Program): StructureIsReused {
   return (program as any).structureIsReused;
-}
\ No newline at end of file
+}
+
+export function createMessageDiagnostic(messageText: string): ts.Diagnostic&Diagnostic {
+  return {
+    file: undefined,
+    start: undefined,
+    length: undefined,
+    category: ts.DiagnosticCategory.Message, messageText,
+    code: DEFAULT_ERROR_CODE,
+    source: SOURCE,
+  };
+}
diff --git a/packages/compiler-cli/test/ngc_spec.ts b/packages/compiler-cli/test/ngc_spec.ts
index 61cd86d2f6..e787aeacf9 100644
--- a/packages/compiler-cli/test/ngc_spec.ts
+++ b/packages/compiler-cli/test/ngc_spec.ts
@@ -336,18 +336,21 @@ describe('ngc transformer command-line', () => {
         });
       }
 
-      function expectAllGeneratedFilesToExist() {
+      function expectAllGeneratedFilesToExist(enableSummariesForJit = true) {
         modules.forEach(moduleName => {
           if (/module|comp/.test(moduleName)) {
             shouldExist(moduleName + '.ngfactory.js');
             shouldExist(moduleName + '.ngfactory.d.ts');
-            shouldExist(moduleName + '.ngsummary.js');
-            shouldExist(moduleName + '.ngsummary.d.ts');
           } else {
             shouldNotExist(moduleName + '.ngfactory.js');
             shouldNotExist(moduleName + '.ngfactory.d.ts');
+          }
+          if (enableSummariesForJit) {
             shouldExist(moduleName + '.ngsummary.js');
             shouldExist(moduleName + '.ngsummary.d.ts');
+          } else {
+            shouldNotExist(moduleName + '.ngsummary.js');
+            shouldNotExist(moduleName + '.ngsummary.d.ts');
           }
           shouldExist(moduleName + '.ngsummary.json');
           shouldNotExist(moduleName + '.ngfactory.metadata.json');
@@ -359,10 +362,11 @@ describe('ngc transformer command-line', () => {
         shouldExist('emulated.css.shim.ngstyle.d.ts');
       }
 
-      it('should emit generated files from sources', () => {
+      it('should emit generated files from sources with summariesForJit', () => {
         writeConfig(`{
             "extends": "./tsconfig-base.json",
             "angularCompilerOptions": {
+              "enableSummariesForJit": true
             },
             "include": ["src/**/*.ts"]
           }`);
@@ -370,7 +374,22 @@ describe('ngc transformer command-line', () => {
         expect(exitCode).toEqual(0);
         outDir = path.resolve(basePath, 'built', 'src');
         expectJsDtsMetadataJsonToExist();
-        expectAllGeneratedFilesToExist();
+        expectAllGeneratedFilesToExist(true);
+      });
+
+      it('should not emit generated files from sources without summariesForJit', () => {
+        writeConfig(`{
+            "extends": "./tsconfig-base.json",
+            "angularCompilerOptions": {
+              "enableSummariesForJit": false
+            },
+            "include": ["src/**/*.ts"]
+          }`);
+        const exitCode = main(['-p', path.join(basePath, 'tsconfig.json')], errorSpy);
+        expect(exitCode).toEqual(0);
+        outDir = path.resolve(basePath, 'built', 'src');
+        expectJsDtsMetadataJsonToExist();
+        expectAllGeneratedFilesToExist(false);
       });
 
       it('should emit generated files from libraries', () => {
@@ -408,7 +427,8 @@ describe('ngc transformer command-line', () => {
         writeConfig(`{
             "extends": "./tsconfig-base.json",
             "angularCompilerOptions": {
-              "skipTemplateCodegen": false
+              "skipTemplateCodegen": false,
+              "enableSummariesForJit": true
             },
             "compilerOptions": {
               "outDir": "built"
@@ -880,7 +900,8 @@ describe('ngc transformer command-line', () => {
       write('tsconfig-ng.json', `{
           "extends": "./tsconfig-base.json",
           "angularCompilerOptions": {
-            "generateCodeForLibraries": true
+            "generateCodeForLibraries": true,
+            "enableSummariesForJit": true
           },
           "compilerOptions": {
             "outDir": "."
@@ -896,7 +917,8 @@ describe('ngc transformer command-line', () => {
       write('lib1/tsconfig-lib1.json', `{
           "extends": "../tsconfig-base.json",
           "angularCompilerOptions": {
-            "generateCodeForLibraries": false
+            "generateCodeForLibraries": false,
+            "enableSummariesForJit": true
           },
           "compilerOptions": {
             "rootDir": ".",
@@ -919,7 +941,8 @@ describe('ngc transformer command-line', () => {
       write('lib2/tsconfig-lib2.json', `{
           "extends": "../tsconfig-base.json",
           "angularCompilerOptions": {
-            "generateCodeForLibraries": false
+            "generateCodeForLibraries": false,
+            "enableSummariesForJit": true
           },
           "compilerOptions": {
             "rootDir": ".",
@@ -941,7 +964,8 @@ describe('ngc transformer command-line', () => {
       write('app/tsconfig-app.json', `{
           "extends": "../tsconfig-base.json",
           "angularCompilerOptions": {
-            "generateCodeForLibraries": false
+            "generateCodeForLibraries": false,
+            "enableSummariesForJit": true
           },
           "compilerOptions": {
             "rootDir": ".",
diff --git a/packages/compiler-cli/test/perform_watch_spec.ts b/packages/compiler-cli/test/perform_watch_spec.ts
index 6bac15f01c..ae0184e2c2 100644
--- a/packages/compiler-cli/test/perform_watch_spec.ts
+++ b/packages/compiler-cli/test/perform_watch_spec.ts
@@ -86,10 +86,9 @@ describe('perform watch', () => {
 
     // trigger a single file change
     // -> all other files should be cached
-    fs.unlinkSync(mainNgFactory);
     host.triggerFileChange(FileChangeEvent.Change, utilTsPath);
+    expectNoDiagnostics(config.options, host.diagnostics);
 
-    expect(fs.existsSync(mainNgFactory)).toBe(true);
     expect(fileExistsSpy !).not.toHaveBeenCalledWith(mainTsPath);
     expect(fileExistsSpy !).toHaveBeenCalledWith(utilTsPath);
     expect(getSourceFileSpy !).not.toHaveBeenCalledWith(mainTsPath, ts.ScriptTarget.ES5);
@@ -97,11 +96,10 @@ describe('perform watch', () => {
 
     // trigger a folder change
     // -> nothing should be cached
-    fs.unlinkSync(mainNgFactory);
     host.triggerFileChange(
         FileChangeEvent.CreateDeleteDir, path.resolve(testSupport.basePath, 'src'));
+    expectNoDiagnostics(config.options, host.diagnostics);
 
-    expect(fs.existsSync(mainNgFactory)).toBe(true);
     expect(fileExistsSpy !).toHaveBeenCalledWith(mainTsPath);
     expect(fileExistsSpy !).toHaveBeenCalledWith(utilTsPath);
     expect(getSourceFileSpy !).toHaveBeenCalledWith(mainTsPath, ts.ScriptTarget.ES5);
diff --git a/packages/compiler-cli/test/test_support.ts b/packages/compiler-cli/test/test_support.ts
index 8845e2275d..38dd9e9678 100644
--- a/packages/compiler-cli/test/test_support.ts
+++ b/packages/compiler-cli/test/test_support.ts
@@ -110,8 +110,9 @@ export function setup(): TestSupport {
 }
 
 export function expectNoDiagnostics(options: ng.CompilerOptions, diags: ng.Diagnostics) {
-  if (diags.length) {
-    throw new Error(`Expected no diagnostics: ${ng.formatDiagnostics(options, diags)}`);
+  const errorDiags = diags.filter(d => d.category !== ts.DiagnosticCategory.Message);
+  if (errorDiags.length) {
+    throw new Error(`Expected no diagnostics: ${ng.formatDiagnostics(options, errorDiags)}`);
   }
 }
 
diff --git a/packages/compiler-cli/test/transformers/compiler_host_spec.ts b/packages/compiler-cli/test/transformers/compiler_host_spec.ts
index e2579a7e53..d597fb8ce2 100644
--- a/packages/compiler-cli/test/transformers/compiler_host_spec.ts
+++ b/packages/compiler-cli/test/transformers/compiler_host_spec.ts
@@ -51,7 +51,7 @@ describe('NgCompilerHost', () => {
   } = {}) {
     return new TsCompilerAotCompilerTypeCheckHostAdapter(
         ['/tmp/index.ts'], options, ngHost, new MetadataCollector(), codeGenerator,
-        librarySummaries);
+        new Map(librarySummaries.map(entry => [entry.fileName, entry] as[string, LibrarySummary])));
   }
 
   describe('fileNameToModuleName', () => {
diff --git a/packages/compiler-cli/test/transformers/program_spec.ts b/packages/compiler-cli/test/transformers/program_spec.ts
index 9db67d4aa7..def4fd1db4 100644
--- a/packages/compiler-cli/test/transformers/program_spec.ts
+++ b/packages/compiler-cli/test/transformers/program_spec.ts
@@ -57,17 +57,20 @@ describe('ng program', () => {
   }
 
   function compile(
-      oldProgram?: ng.Program, overrideOptions?: ng.CompilerOptions,
-      rootNames?: string[]): ng.Program {
+      oldProgram?: ng.Program, overrideOptions?: ng.CompilerOptions, rootNames?: string[],
+      host?: CompilerHost): ng.Program {
     const options = testSupport.createCompilerOptions(overrideOptions);
     if (!rootNames) {
       rootNames = [path.resolve(testSupport.basePath, 'src/index.ts')];
     }
-
+    if (!host) {
+      host = ng.createCompilerHost({options});
+    }
     const program = ng.createProgram({
       rootNames: rootNames,
       options,
-      host: ng.createCompilerHost({options}), oldProgram,
+      host,
+      oldProgram,
     });
     expectNoDiagnosticsInProgram(options, program);
     program.emit();
@@ -153,6 +156,59 @@ describe('ng program', () => {
              .toBe(false);
        });
 
+    it('should only emit changed files', () => {
+      testSupport.writeFiles({
+        'src/index.ts': createModuleAndCompSource('comp', 'index.html'),
+        'src/index.html': `Start`
+      });
+      const options: ng.CompilerOptions = {declaration: false};
+      const host = ng.createCompilerHost({options});
+      const originalGetSourceFile = host.getSourceFile;
+      const fileCache = new Map<string, ts.SourceFile>();
+      host.getSourceFile = (fileName: string) => {
+        if (fileCache.has(fileName)) {
+          return fileCache.get(fileName);
+        }
+        const sf = originalGetSourceFile.call(host, fileName);
+        fileCache.set(fileName, sf);
+        return sf;
+      };
+
+      const written = new Map<string, string>();
+      host.writeFile = (fileName: string, data: string) => written.set(fileName, data);
+
+      // compile libraries
+      const p1 = compile(undefined, options, undefined, host);
+
+      // first compile without libraries
+      const p2 = compile(p1, options, undefined, host);
+      expect(written.has(path.resolve(testSupport.basePath, 'built/src/index.js'))).toBe(true);
+      let ngFactoryContent =
+          written.get(path.resolve(testSupport.basePath, 'built/src/index.ngfactory.js'));
+      expect(ngFactoryContent).toMatch(/Start/);
+
+      // no change -> no emit
+      written.clear();
+      const p3 = compile(p2, options, undefined, host);
+      expect(written.size).toBe(0);
+
+      // change a user file
+      written.clear();
+      fileCache.delete(path.resolve(testSupport.basePath, 'src/index.ts'));
+      const p4 = compile(p3, options, undefined, host);
+      expect(written.size).toBe(1);
+      expect(written.has(path.resolve(testSupport.basePath, 'built/src/index.js'))).toBe(true);
+
+      // change a file that is input to generated files
+      written.clear();
+      testSupport.writeFiles({'src/index.html': 'Hello'});
+      const p5 = compile(p4, options, undefined, host);
+      expect(written.size).toBe(1);
+      ngFactoryContent =
+          written.get(path.resolve(testSupport.basePath, 'built/src/index.ngfactory.js'));
+      expect(ngFactoryContent).toMatch(/Hello/);
+    });
+
     it('should store library summaries on emit', () => {
       compileLib('lib');
       testSupport.writeFiles({
@@ -163,17 +219,19 @@ describe('ng program', () => {
           `
       });
       const p1 = compile();
-      expect(p1.getLibrarySummaries().some(
-                 sf => /node_modules\/lib\/index\.ngfactory\.d\.ts$/.test(sf.fileName)))
+      expect(Array.from(p1.getLibrarySummaries().values())
+                 .some(sf => /node_modules\/lib\/index\.ngfactory\.d\.ts$/.test(sf.fileName)))
           .toBe(true);
-      expect(p1.getLibrarySummaries().some(
-                 sf => /node_modules\/lib\/index\.ngsummary\.json$/.test(sf.fileName)))
+      expect(Array.from(p1.getLibrarySummaries().values())
+                 .some(sf => /node_modules\/lib\/index\.ngsummary\.json$/.test(sf.fileName)))
           .toBe(true);
-      expect(
-          p1.getLibrarySummaries().some(sf => /node_modules\/lib\/index\.d\.ts$/.test(sf.fileName)))
+      expect(Array.from(p1.getLibrarySummaries().values())
+                 .some(sf => /node_modules\/lib\/index\.d\.ts$/.test(sf.fileName)))
           .toBe(true);
 
-      expect(p1.getLibrarySummaries().some(sf => /src\/main.*$/.test(sf.fileName))).toBe(false);
+      expect(Array.from(p1.getLibrarySummaries().values())
+                 .some(sf => /src\/main.*$/.test(sf.fileName)))
+          .toBe(false);
     });
 
     it('should reuse the old ts program completely if nothing changed', () => {
@@ -300,7 +358,10 @@ describe('ng program', () => {
         export * from './main';
       `,
     });
-    const options = testSupport.createCompilerOptions({allowEmptyCodegenFiles: true});
+    const options = testSupport.createCompilerOptions({
+      allowEmptyCodegenFiles: true,
+      enableSummariesForJit: true,
+    });
     const host = ng.createCompilerHost({options});
     const written = new Map < string, {
       original: ts.SourceFile[]|undefined;
@@ -384,11 +445,11 @@ describe('ng program', () => {
     testSupport.shouldExist('built/main.ngfactory.js');
     testSupport.shouldExist('built/main.ngfactory.d.ts');
     testSupport.shouldExist('built/main.ngsummary.json');
-    testSupport.shouldNotExist('build/node_modules/lib/index.js');
-    testSupport.shouldNotExist('build/node_modules/lib/index.d.ts');
-    testSupport.shouldNotExist('build/node_modules/lib/index.ngfactory.js');
-    testSupport.shouldNotExist('build/node_modules/lib/index.ngfactory.d.ts');
-    testSupport.shouldNotExist('build/node_modules/lib/index.ngsummary.json');
+    testSupport.shouldNotExist('built/node_modules/lib/index.js');
+    testSupport.shouldNotExist('built/node_modules/lib/index.d.ts');
+    testSupport.shouldNotExist('built/node_modules/lib/index.ngfactory.js');
+    testSupport.shouldNotExist('built/node_modules/lib/index.ngfactory.d.ts');
+    testSupport.shouldNotExist('built/node_modules/lib/index.ngsummary.json');
   });
 
   describe('createSrcToOutPathMapper', () => {
diff --git a/packages/compiler/src/aot/compiler.ts b/packages/compiler/src/aot/compiler.ts
index 2f1f7017cd..4da4cc9208 100644
--- a/packages/compiler/src/aot/compiler.ts
+++ b/packages/compiler/src/aot/compiler.ts
@@ -98,7 +98,9 @@ export class AotCompiler {
     if (this._options.allowEmptyCodegenFiles || file.directives.length || file.pipes.length ||
         file.injectables.length || file.ngModules.length || file.exportsNonSourceFiles) {
       genFileNames.push(ngfactoryFilePath(file.fileName, true));
-      genFileNames.push(summaryForJitFileName(file.fileName, true));
+      if (this._options.enableSummariesForJit) {
+        genFileNames.push(summaryForJitFileName(file.fileName, true));
+      }
     }
     const fileSuffix = splitTypescriptSuffix(file.fileName, true)[1];
     file.directives.forEach((dirSymbol) => {
@@ -376,7 +378,9 @@ export class AotCompiler {
                                metadata: this._metadataResolver.getInjectableSummary(ref) !.type
                              }))
         ];
-    const forJitOutputCtx = this._createOutputContext(summaryForJitFileName(srcFileName, true));
+    const forJitOutputCtx = this._options.enableSummariesForJit ?
+        this._createOutputContext(summaryForJitFileName(srcFileName, true)) :
+        null;
     const {json, exportAs} = serializeSummaries(
         srcFileName, forJitOutputCtx, this._summaryResolver, this._symbolResolver, symbolSummaries,
         typeData);
@@ -387,11 +391,11 @@ export class AotCompiler {
           ]));
     });
     const summaryJson = new GeneratedFile(srcFileName, summaryFileName(srcFileName), json);
-    if (this._options.enableSummariesForJit) {
-      return [summaryJson, this._codegenSourceModule(srcFileName, forJitOutputCtx)];
+    const result = [summaryJson];
+    if (forJitOutputCtx) {
+      result.push(this._codegenSourceModule(srcFileName, forJitOutputCtx));
     }
-
-    return [summaryJson];
+    return result;
   }
 
   private _compileModule(outputCtx: OutputContext, ngModule: CompileNgModuleMetadata): void {
diff --git a/packages/compiler/src/aot/compiler_options.ts b/packages/compiler/src/aot/compiler_options.ts
index 1149a4cddf..b7bd69d320 100644
--- a/packages/compiler/src/aot/compiler_options.ts
+++ b/packages/compiler/src/aot/compiler_options.ts
@@ -14,7 +14,6 @@ export interface AotCompilerOptions {
   translations?: string;
   missingTranslation?: MissingTranslationStrategy;
   enableLegacyTemplate?: boolean;
-  /** TODO(tbosch): remove this flag as it is always on in the new ngc */
   enableSummariesForJit?: boolean;
   preserveWhitespaces?: boolean;
   fullTemplateTypeCheck?: boolean;
diff --git a/packages/compiler/src/aot/generated_file.ts b/packages/compiler/src/aot/generated_file.ts
index 226126f4f4..c072e57a90 100644
--- a/packages/compiler/src/aot/generated_file.ts
+++ b/packages/compiler/src/aot/generated_file.ts
@@ -7,7 +7,7 @@
  */
 
 import {sourceUrl} from '../compile_metadata';
-import {Statement} from '../output/output_ast';
+import {Statement, areAllEquivalent} from '../output/output_ast';
 import {TypeScriptEmitter} from '../output/ts_emitter';
 
 export class GeneratedFile {
@@ -24,6 +24,21 @@ export class GeneratedFile {
       this.stmts = sourceOrStmts;
     }
   }
+
+  isEquivalent(other: GeneratedFile): boolean {
+    if (this.genFileUrl !== other.genFileUrl) {
+      return false;
+    }
+    if (this.source) {
+      return this.source === other.source;
+    }
+    if (other.stmts == null) {
+      return false;
+    }
+    // Note: the constructor guarantees that if this.source is not filled,
+    // then this.stmts is.
+    return areAllEquivalent(this.stmts !, other.stmts !);
+  }
 }
 
 export function toTypeScript(file: GeneratedFile, preamble: string = ''): string {
diff --git a/packages/compiler/src/aot/summary_serializer.ts b/packages/compiler/src/aot/summary_serializer.ts
index 43de1da9bf..765b06d38d 100644
--- a/packages/compiler/src/aot/summary_serializer.ts
+++ b/packages/compiler/src/aot/summary_serializer.ts
@@ -15,14 +15,14 @@ import {ResolvedStaticSymbol, StaticSymbolResolver} from './static_symbol_resolv
 import {summaryForJitFileName, summaryForJitName} from './util';
 
 export function serializeSummaries(
-    srcFileName: string, forJitCtx: OutputContext, summaryResolver: SummaryResolver<StaticSymbol>,
-    symbolResolver: StaticSymbolResolver, symbols: ResolvedStaticSymbol[], types: {
+    srcFileName: string, forJitCtx: OutputContext | null,
+    summaryResolver: SummaryResolver<StaticSymbol>, symbolResolver: StaticSymbolResolver,
+    symbols: ResolvedStaticSymbol[], types: {
       summary: CompileTypeSummary,
       metadata: CompileNgModuleMetadata | CompileDirectiveMetadata | CompilePipeMetadata |
           CompileTypeMetadata
     }[]): {json: string, exportAs: {symbol: StaticSymbol, exportAs: string}[]} {
   const toJsonSerializer = new ToJsonSerializer(symbolResolver, summaryResolver, srcFileName);
-  const forJitSerializer = new ForJitSerializer(forJitCtx, symbolResolver);
 
   // for symbols, we use everything except for the class metadata itself
   // (we keep the statics though), as the class metadata is contained in the
@@ -33,18 +33,20 @@ export function serializeSummaries(
 
   // Add type summaries.
   types.forEach(({summary, metadata}) => {
-    forJitSerializer.addSourceType(summary, metadata);
     toJsonSerializer.addSummary(
         {symbol: summary.type.reference, metadata: undefined, type: summary});
   });
-  toJsonSerializer.unprocessedSymbolSummariesBySymbol.forEach((summary) => {
-    if (summaryResolver.isLibraryFile(summary.symbol.filePath) && summary.type) {
-      forJitSerializer.addLibType(summary.type);
-    }
-  });
-
   const {json, exportAs} = toJsonSerializer.serialize();
-  forJitSerializer.serialize(exportAs);
+  if (forJitCtx) {
+    const forJitSerializer = new ForJitSerializer(forJitCtx, symbolResolver);
+    types.forEach(({summary, metadata}) => { forJitSerializer.addSourceType(summary, metadata); });
+    toJsonSerializer.unprocessedSymbolSummariesBySymbol.forEach((summary) => {
+      if (summaryResolver.isLibraryFile(summary.symbol.filePath) && summary.type) {
+        forJitSerializer.addLibType(summary.type);
+      }
+    });
+    forJitSerializer.serialize(exportAs);
+  }
   return {json, exportAs};
 }
 
diff --git a/packages/compiler/src/output/output_ast.ts b/packages/compiler/src/output/output_ast.ts
index afa3567f19..ab0e561d56 100644
--- a/packages/compiler/src/output/output_ast.ts
+++ b/packages/compiler/src/output/output_ast.ts
@@ -104,6 +104,27 @@ export enum BinaryOperator {
   BiggerEquals
 }
 
+export function nullSafeIsEquivalent<T extends{isEquivalent(other: T): boolean}>(
+    base: T | null, other: T | null) {
+  if (base == null || other == null) {
+    return base == other;
+  }
+  return base.isEquivalent(other);
+}
+
+export function areAllEquivalent<T extends{isEquivalent(other: T): boolean}>(
+    base: T[], other: T[]) {
+  const len = base.length;
+  if (len !== other.length) {
+    return false;
+  }
+  for (let i = 0; i < len; i++) {
+    if (!base[i].isEquivalent(other[i])) {
+      return false;
+    }
+  }
+  return true;
+}
 
 export abstract class Expression {
   public type: Type|null;
@@ -116,6 +137,12 @@ export abstract class Expression {
 
   abstract visitExpression(visitor: ExpressionVisitor, context: any): any;
 
+  /**
+   * Calculates whether this expression produces the same value as the given expression.
+   * Note: We don't check Types nor ParseSourceSpans nor function arguments.
+   */
+  abstract isEquivalent(e: Expression): boolean;
+
   prop(name: string, sourceSpan?: ParseSourceSpan|null): ReadPropExpr {
     return new ReadPropExpr(this, name, null, sourceSpan);
   }
@@ -222,6 +249,10 @@ export class ReadVarExpr extends Expression {
       this.builtin = <BuiltinVar>name;
     }
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof ReadVarExpr && this.name === e.name && this.builtin === e.builtin;
+  }
+
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitReadVarExpr(this, context);
   }
@@ -242,6 +273,9 @@ export class WriteVarExpr extends Expression {
     super(type || value.type, sourceSpan);
     this.value = value;
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof WriteVarExpr && this.name === e.name && this.value.isEquivalent(e.value);
+  }
 
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitWriteVarExpr(this, context);
@@ -261,6 +295,10 @@ export class WriteKeyExpr extends Expression {
     super(type || value.type, sourceSpan);
     this.value = value;
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof WriteKeyExpr && this.receiver.isEquivalent(e.receiver) &&
+        this.index.isEquivalent(e.index) && this.value.isEquivalent(e.value);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitWriteKeyExpr(this, context);
   }
@@ -275,6 +313,10 @@ export class WritePropExpr extends Expression {
     super(type || value.type, sourceSpan);
     this.value = value;
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof WritePropExpr && this.receiver.isEquivalent(e.receiver) &&
+        this.name === e.name && this.value.isEquivalent(e.value);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitWritePropExpr(this, context);
   }
@@ -301,6 +343,10 @@ export class InvokeMethodExpr extends Expression {
       this.builtin = <BuiltinMethod>method;
     }
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof InvokeMethodExpr && this.receiver.isEquivalent(e.receiver) &&
+        this.name === e.name && this.builtin === e.builtin && areAllEquivalent(this.args, e.args);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitInvokeMethodExpr(this, context);
   }
@@ -313,6 +359,10 @@ export class InvokeFunctionExpr extends Expression {
       sourceSpan?: ParseSourceSpan|null) {
     super(type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof InvokeFunctionExpr && this.fn.isEquivalent(e.fn) &&
+        areAllEquivalent(this.args, e.args);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitInvokeFunctionExpr(this, context);
   }
@@ -325,6 +375,10 @@ export class InstantiateExpr extends Expression {
       sourceSpan?: ParseSourceSpan|null) {
     super(type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof InstantiateExpr && this.classExpr.isEquivalent(e.classExpr) &&
+        areAllEquivalent(this.args, e.args);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitInstantiateExpr(this, context);
   }
@@ -332,9 +386,14 @@ export class InstantiateExpr extends Expression {
 
 
 export class LiteralExpr extends Expression {
-  constructor(public value: any, type?: Type|null, sourceSpan?: ParseSourceSpan|null) {
+  constructor(
+      public value: number|string|boolean|null|undefined, type?: Type|null,
+      sourceSpan?: ParseSourceSpan|null) {
     super(type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof LiteralExpr && this.value === e.value;
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitLiteralExpr(this, context);
   }
@@ -347,6 +406,10 @@ export class ExternalExpr extends Expression {
       sourceSpan?: ParseSourceSpan|null) {
     super(type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof ExternalExpr && this.value.name === e.value.name &&
+        this.value.moduleName === e.value.moduleName && this.value.runtime === e.value.runtime;
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitExternalExpr(this, context);
   }
@@ -355,6 +418,7 @@ export class ExternalExpr extends Expression {
 export class ExternalReference {
   constructor(public moduleName: string|null, public name: string|null, public runtime?: any|null) {
   }
+  // Note: no isEquivalent method here as we use this as an interface too.
 }
 
 export class ConditionalExpr extends Expression {
@@ -365,6 +429,10 @@ export class ConditionalExpr extends Expression {
     super(type || trueCase.type, sourceSpan);
     this.trueCase = trueCase;
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof ConditionalExpr && this.condition.isEquivalent(e.condition) &&
+        this.trueCase.isEquivalent(e.trueCase) && nullSafeIsEquivalent(this.falseCase, e.falseCase);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitConditionalExpr(this, context);
   }
@@ -375,6 +443,9 @@ export class NotExpr extends Expression {
   constructor(public condition: Expression, sourceSpan?: ParseSourceSpan|null) {
     super(BOOL_TYPE, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof NotExpr && this.condition.isEquivalent(e.condition);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitNotExpr(this, context);
   }
@@ -384,6 +455,9 @@ export class AssertNotNull extends Expression {
   constructor(public condition: Expression, sourceSpan?: ParseSourceSpan|null) {
     super(condition.type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof AssertNotNull && this.condition.isEquivalent(e.condition);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitAssertNotNullExpr(this, context);
   }
@@ -393,6 +467,9 @@ export class CastExpr extends Expression {
   constructor(public value: Expression, type?: Type|null, sourceSpan?: ParseSourceSpan|null) {
     super(type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof CastExpr && this.value.isEquivalent(e.value);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitCastExpr(this, context);
   }
@@ -401,6 +478,8 @@ export class CastExpr extends Expression {
 
 export class FnParam {
   constructor(public name: string, public type: Type|null = null) {}
+
+  isEquivalent(param: FnParam): boolean { return this.name === param.name; }
 }
 
 
@@ -410,6 +489,10 @@ export class FunctionExpr extends Expression {
       sourceSpan?: ParseSourceSpan|null) {
     super(type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof FunctionExpr && areAllEquivalent(this.params, e.params) &&
+        areAllEquivalent(this.statements, e.statements);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitFunctionExpr(this, context);
   }
@@ -429,6 +512,10 @@ export class BinaryOperatorExpr extends Expression {
     super(type || lhs.type, sourceSpan);
     this.lhs = lhs;
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof BinaryOperatorExpr && this.operator === e.operator &&
+        this.lhs.isEquivalent(e.lhs) && this.rhs.isEquivalent(e.rhs);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitBinaryOperatorExpr(this, context);
   }
@@ -441,6 +528,10 @@ export class ReadPropExpr extends Expression {
       sourceSpan?: ParseSourceSpan|null) {
     super(type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof ReadPropExpr && this.receiver.isEquivalent(e.receiver) &&
+        this.name === e.name;
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitReadPropExpr(this, context);
   }
@@ -456,6 +547,10 @@ export class ReadKeyExpr extends Expression {
       sourceSpan?: ParseSourceSpan|null) {
     super(type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof ReadKeyExpr && this.receiver.isEquivalent(e.receiver) &&
+        this.index.isEquivalent(e.index);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitReadKeyExpr(this, context);
   }
@@ -471,6 +566,9 @@ export class LiteralArrayExpr extends Expression {
     super(type, sourceSpan);
     this.entries = entries;
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof LiteralArrayExpr && areAllEquivalent(this.entries, e.entries);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitLiteralArrayExpr(this, context);
   }
@@ -478,6 +576,9 @@ export class LiteralArrayExpr extends Expression {
 
 export class LiteralMapEntry {
   constructor(public key: string, public value: Expression, public quoted: boolean) {}
+  isEquivalent(e: LiteralMapEntry): boolean {
+    return this.key === e.key && this.value.isEquivalent(e.value);
+  }
 }
 
 export class LiteralMapExpr extends Expression {
@@ -489,6 +590,9 @@ export class LiteralMapExpr extends Expression {
       this.valueType = type.valueType;
     }
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof LiteralMapExpr && areAllEquivalent(this.entries, e.entries);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitLiteralMapExpr(this, context);
   }
@@ -498,6 +602,9 @@ export class CommaExpr extends Expression {
   constructor(public parts: Expression[], sourceSpan?: ParseSourceSpan|null) {
     super(parts[parts.length - 1].type, sourceSpan);
   }
+  isEquivalent(e: Expression): boolean {
+    return e instanceof CommaExpr && areAllEquivalent(this.parts, e.parts);
+  }
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitCommaExpr(this, context);
   }
@@ -547,6 +654,11 @@ export abstract class Statement {
     this.modifiers = modifiers || [];
     this.sourceSpan = sourceSpan || null;
   }
+  /**
+   * Calculates whether this statement produces the same value as the given statement.
+   * Note: We don't check Types nor ParseSourceSpans nor function arguments.
+   */
+  abstract isEquivalent(stmt: Statement): boolean;
 
   abstract visitStatement(visitor: StatementVisitor, context: any): any;
 
@@ -562,7 +674,10 @@ export class DeclareVarStmt extends Statement {
     super(modifiers, sourceSpan);
     this.type = type || value.type;
   }
-
+  isEquivalent(stmt: Statement): boolean {
+    return stmt instanceof DeclareVarStmt && this.name === stmt.name &&
+        this.value.isEquivalent(stmt.value);
+  }
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitDeclareVarStmt(this, context);
   }
@@ -576,6 +691,10 @@ export class DeclareFunctionStmt extends Statement {
     super(modifiers, sourceSpan);
     this.type = type || null;
   }
+  isEquivalent(stmt: Statement): boolean {
+    return stmt instanceof DeclareFunctionStmt && areAllEquivalent(this.params, stmt.params) &&
+        areAllEquivalent(this.statements, stmt.statements);
+  }
 
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitDeclareFunctionStmt(this, context);
@@ -586,6 +705,9 @@ export class ExpressionStatement extends Statement {
   constructor(public expr: Expression, sourceSpan?: ParseSourceSpan|null) {
     super(null, sourceSpan);
   }
+  isEquivalent(stmt: Statement): boolean {
+    return stmt instanceof ExpressionStatement && this.expr.isEquivalent(stmt.expr);
+  }
 
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitExpressionStmt(this, context);
@@ -597,6 +719,9 @@ export class ReturnStatement extends Statement {
   constructor(public value: Expression, sourceSpan?: ParseSourceSpan|null) {
     super(null, sourceSpan);
   }
+  isEquivalent(stmt: Statement): boolean {
+    return stmt instanceof ReturnStatement && this.value.isEquivalent(stmt.value);
+  }
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitReturnStmt(this, context);
   }
@@ -617,6 +742,7 @@ export class ClassField extends AbstractClassPart {
   constructor(public name: string, type?: Type|null, modifiers: StmtModifier[]|null = null) {
     super(type, modifiers);
   }
+  isEquivalent(f: ClassField) { return this.name === f.name; }
 }
 
 
@@ -626,6 +752,9 @@ export class ClassMethod extends AbstractClassPart {
       type?: Type|null, modifiers: StmtModifier[]|null = null) {
     super(type, modifiers);
   }
+  isEquivalent(m: ClassMethod) {
+    return this.name === m.name && areAllEquivalent(this.body, m.body);
+  }
 }
 
 
@@ -635,6 +764,9 @@ export class ClassGetter extends AbstractClassPart {
       modifiers: StmtModifier[]|null = null) {
     super(type, modifiers);
   }
+  isEquivalent(m: ClassGetter) {
+    return this.name === m.name && areAllEquivalent(this.body, m.body);
+  }
 }
 
 
@@ -646,6 +778,14 @@ export class ClassStmt extends Statement {
       sourceSpan?: ParseSourceSpan|null) {
     super(modifiers, sourceSpan);
   }
+  isEquivalent(stmt: Statement): boolean {
+    return stmt instanceof ClassStmt && this.name === stmt.name &&
+        nullSafeIsEquivalent(this.parent, stmt.parent) &&
+        areAllEquivalent(this.fields, stmt.fields) &&
+        areAllEquivalent(this.getters, stmt.getters) &&
+        this.constructorMethod.isEquivalent(stmt.constructorMethod) &&
+        areAllEquivalent(this.methods, stmt.methods);
+  }
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitDeclareClassStmt(this, context);
   }
@@ -658,6 +798,11 @@ export class IfStmt extends Statement {
       public falseCase: Statement[] = [], sourceSpan?: ParseSourceSpan|null) {
     super(null, sourceSpan);
   }
+  isEquivalent(stmt: Statement): boolean {
+    return stmt instanceof IfStmt && this.condition.isEquivalent(stmt.condition) &&
+        areAllEquivalent(this.trueCase, stmt.trueCase) &&
+        areAllEquivalent(this.falseCase, stmt.falseCase);
+  }
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitIfStmt(this, context);
   }
@@ -668,6 +813,7 @@ export class CommentStmt extends Statement {
   constructor(public comment: string, sourceSpan?: ParseSourceSpan|null) {
     super(null, sourceSpan);
   }
+  isEquivalent(stmt: Statement): boolean { return stmt instanceof CommentStmt; }
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitCommentStmt(this, context);
   }
@@ -680,6 +826,10 @@ export class TryCatchStmt extends Statement {
       sourceSpan?: ParseSourceSpan|null) {
     super(null, sourceSpan);
   }
+  isEquivalent(stmt: Statement): boolean {
+    return stmt instanceof TryCatchStmt && areAllEquivalent(this.bodyStmts, stmt.bodyStmts) &&
+        areAllEquivalent(this.catchStmts, stmt.catchStmts);
+  }
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitTryCatchStmt(this, context);
   }
@@ -690,6 +840,9 @@ export class ThrowStmt extends Statement {
   constructor(public error: Expression, sourceSpan?: ParseSourceSpan|null) {
     super(null, sourceSpan);
   }
+  isEquivalent(stmt: ThrowStmt): boolean {
+    return stmt instanceof TryCatchStmt && this.error.isEquivalent(stmt.error);
+  }
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitThrowStmt(this, context);
   }
diff --git a/packages/upgrade/src/common/downgrade_component.ts b/packages/upgrade/src/common/downgrade_component.ts
index 14ebc80738..a6d736582c 100644
--- a/packages/upgrade/src/common/downgrade_component.ts
+++ b/packages/upgrade/src/common/downgrade_component.ts
@@ -115,7 +115,7 @@ export function downgradeComponent(info: {
           facade.createComponent(projectableNodes);
           facade.setupInputs(needsNgZone, info.propagateDigest);
           facade.setupOutputs();
-          facade.registerCleanup(needsNgZone);
+          facade.registerCleanup();
 
           injectorPromise.resolve(facade.getInjector());
 
diff --git a/packages/upgrade/src/common/downgrade_component_adapter.ts b/packages/upgrade/src/common/downgrade_component_adapter.ts
index 13bb1ed9a4..74509791f5 100644
--- a/packages/upgrade/src/common/downgrade_component_adapter.ts
+++ b/packages/upgrade/src/common/downgrade_component_adapter.ts
@@ -25,7 +25,6 @@ export class DowngradeComponentAdapter {
   private componentRef: ComponentRef<any>;
   private component: any;
   private changeDetector: ChangeDetectorRef;
-  private appRef: ApplicationRef;
 
   constructor(
       private element: angular.IAugmentedJQuery, private attrs: angular.IAttributes,
@@ -35,7 +34,6 @@ export class DowngradeComponentAdapter {
       private componentFactory: ComponentFactory<any>,
       private wrapCallback: <T>(cb: () => T) => () => T) {
     this.componentScope = scope.$new();
-    this.appRef = parentInjector.get(ApplicationRef);
   }
 
   compileContents(): Node[][] {
@@ -101,7 +99,7 @@ export class DowngradeComponentAdapter {
         })(input.prop);
         attrs.$observe(input.attr, observeFn);
 
-        // Use `$watch()` (in addition to `$observe()`) in order to initialize the input  in time
+        // Use `$watch()` (in addition to `$observe()`) in order to initialize the input in time
         // for `ngOnChanges()`. This is necessary if we are already in a `$digest`, which means that
         // `ngOnChanges()` (which is called by a watcher) will run before the `$observe()` callback.
         let unwatch: Function|null = this.componentScope.$watch(() => {
@@ -140,8 +138,7 @@ export class DowngradeComponentAdapter {
         (<OnChanges>this.component).ngOnChanges(inputChanges !);
       }
 
-      // If opted out of propagating digests, invoke change detection
-      // when inputs change
+      // If opted out of propagating digests, invoke change detection when inputs change.
       if (!propagateDigest) {
         detectChanges();
       }
@@ -152,9 +149,16 @@ export class DowngradeComponentAdapter {
       this.componentScope.$watch(this.wrapCallback(detectChanges));
     }
 
-    // Attach the view so that it will be dirty-checked.
-    if (needsNgZone) {
-      this.appRef.attachView(this.componentRef.hostView);
+    // If necessary, attach the view so that it will be dirty-checked.
+    // (Allow time for the initial input values to be set and `ngOnChanges()` to be called.)
+    if (needsNgZone || !propagateDigest) {
+      let unwatch: Function|null = this.componentScope.$watch(() => {
+        unwatch !();
+        unwatch = null;
+
+        const appRef = this.parentInjector.get<ApplicationRef>(ApplicationRef);
+        appRef.attachView(this.componentRef.hostView);
+      });
     }
   }
 
@@ -202,15 +206,14 @@ export class DowngradeComponentAdapter {
     }
   }
 
-  registerCleanup(needsNgZone: boolean) {
+  registerCleanup() {
+    const destroyComponentRef = this.wrapCallback(() => this.componentRef.destroy());
+
     this.element.on !('$destroy', () => {
       this.componentScope.$destroy();
       this.componentRef.injector.get(TestabilityRegistry)
           .unregisterApplication(this.componentRef.location.nativeElement);
-      this.componentRef.destroy();
-      if (needsNgZone) {
-        this.appRef.detachView(this.componentRef.hostView);
-      }
+      destroyComponentRef();
     });
   }
 
diff --git a/packages/upgrade/test/common/downgrade_component_adapter_spec.ts b/packages/upgrade/test/common/downgrade_component_adapter_spec.ts
index d2656ecf1e..7f91397afe 100644
--- a/packages/upgrade/test/common/downgrade_component_adapter_spec.ts
+++ b/packages/upgrade/test/common/downgrade_component_adapter_spec.ts
@@ -122,7 +122,7 @@ export function main() {
         let $compile = undefined as any;
         let $parse = undefined as any;
         let componentFactory: ComponentFactory<any>;  // testbed
-        let wrapCallback = undefined as any;
+        let wrapCallback = (cb: any) => cb;
 
         content = `
           <h1> new component </h1>
@@ -183,7 +183,7 @@ export function main() {
         expect(registry.getAllTestabilities().length).toEqual(0);
         adapter.createComponent([]);
         expect(registry.getAllTestabilities().length).toEqual(1);
-        adapter.registerCleanup(true);
+        adapter.registerCleanup();
         element.remove !();
         expect(registry.getAllTestabilities().length).toEqual(0);
       });
diff --git a/packages/upgrade/test/static/integration/downgrade_component_spec.ts b/packages/upgrade/test/static/integration/downgrade_component_spec.ts
index bbc3e525ec..01906ec5c2 100644
--- a/packages/upgrade/test/static/integration/downgrade_component_spec.ts
+++ b/packages/upgrade/test/static/integration/downgrade_component_spec.ts
@@ -7,7 +7,7 @@
  */
 
 import {ChangeDetectorRef, Compiler, Component, ComponentFactoryResolver, EventEmitter, Injector, Input, NgModule, NgModuleRef, OnChanges, OnDestroy, SimpleChanges, destroyPlatform} from '@angular/core';
-import {async} from '@angular/core/testing';
+import {async, fakeAsync, tick} from '@angular/core/testing';
 import {BrowserModule} from '@angular/platform-browser';
 import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
 import * as angular from '@angular/upgrade/src/common/angular1';
@@ -274,6 +274,42 @@ export function main() {
          });
        }));
 
+    it('should still run normal Angular change-detection regardless of `propagateDigest`',
+       fakeAsync(() => {
+         let ng2Component: Ng2Component;
+
+         @Component({selector: 'ng2', template: '{{ value }}'})
+         class Ng2Component {
+           value = 'foo';
+           constructor() { setTimeout(() => this.value = 'bar', 1000); }
+         }
+
+         @NgModule({
+           imports: [BrowserModule, UpgradeModule],
+           declarations: [Ng2Component],
+           entryComponents: [Ng2Component]
+         })
+         class Ng2Module {
+           ngDoBootstrap() {}
+         }
+
+         const ng1Module =
+             angular.module('ng1', [])
+                 .directive(
+                     'ng2A', downgradeComponent({component: Ng2Component, propagateDigest: true}))
+                 .directive(
+                     'ng2B', downgradeComponent({component: Ng2Component, propagateDigest: false}));
+
+         const element = html('<ng2-a></ng2-a> | <ng2-b></ng2-b>');
+
+         bootstrap(platformBrowserDynamic(), Ng2Module, element, ng1Module).then(upgrade => {
+           expect(element.textContent).toBe('foo | foo');
+
+           tick(1000);
+           expect(element.textContent).toBe('bar | bar');
+         });
+       }));
+
     it('should initialize inputs in time for `ngOnChanges`', async(() => {
          @Component({
            selector: 'ng2',
diff --git a/packages/upgrade/test/static/integration/downgrade_module_spec.ts b/packages/upgrade/test/static/integration/downgrade_module_spec.ts
index 4544e5c7b7..52e2da16dd 100644
--- a/packages/upgrade/test/static/integration/downgrade_module_spec.ts
+++ b/packages/upgrade/test/static/integration/downgrade_module_spec.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Component, Inject, Injector, Input, NgModule, NgZone, OnChanges, StaticProvider, destroyPlatform} from '@angular/core';
+import {AfterContentChecked, AfterContentInit, AfterViewChecked, AfterViewInit, ApplicationRef, Component, DoCheck, Inject, Injector, Input, NgModule, NgZone, OnChanges, OnDestroy, OnInit, StaticProvider, ViewRef, destroyPlatform} from '@angular/core';
 import {async, fakeAsync, tick} from '@angular/core/testing';
 import {BrowserModule} from '@angular/platform-browser';
 import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
@@ -16,7 +16,7 @@ import {$ROOT_SCOPE, INJECTOR_KEY, LAZY_MODULE_REF} from '@angular/upgrade/src/c
 import {LazyModuleRef} from '@angular/upgrade/src/common/util';
 import {downgradeComponent, downgradeModule} from '@angular/upgrade/static';
 
-import {html} from '../test_helpers';
+import {html, multiTrim} from '../test_helpers';
 
 
 export function main() {
@@ -170,6 +170,42 @@ export function main() {
            });
          }));
 
+      it('should destroy components inside the Angular zone', async(() => {
+           let destroyedInTheZone = false;
+
+           @Component({selector: 'ng2', template: ''})
+           class Ng2Component implements OnDestroy {
+             ngOnDestroy() { destroyedInTheZone = NgZone.isInAngularZone(); }
+           }
+
+           @NgModule({
+             declarations: [Ng2Component],
+             entryComponents: [Ng2Component],
+             imports: [BrowserModule],
+           })
+           class Ng2Module {
+             ngDoBootstrap() {}
+           }
+
+           const bootstrapFn = (extraProviders: StaticProvider[]) =>
+               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
+           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
+           const ng1Module =
+               angular.module('ng1', [lazyModuleName])
+                   .directive(
+                       'ng2', downgradeComponent({component: Ng2Component, propagateDigest}));
+
+           const element = html('<ng2 ng-if="!hideNg2"></ng2>');
+           const $injector = angular.bootstrap(element, [ng1Module.name]);
+           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;
+
+           // Wait for the module to be bootstrapped.
+           setTimeout(() => {
+             $rootScope.$apply('hideNg2 = true');
+             expect(destroyedInTheZone).toBe(true);
+           });
+         }));
+
       it('should propagate input changes inside the Angular zone', async(() => {
            let ng2Component: Ng2Component;
 
@@ -270,6 +306,210 @@ export function main() {
            });
          }));
 
+      it('should run the lifecycle hooks in the correct order', async(() => {
+           const logs: string[] = [];
+           let rootScope: angular.IRootScopeService;
+
+           @Component({
+             selector: 'ng2',
+             template: `
+               {{ value }}
+               <button (click)="value = 'qux'"></button>
+               <ng-content></ng-content>
+             `
+           })
+           class Ng2Component implements AfterContentChecked,
+               AfterContentInit, AfterViewChecked, AfterViewInit, DoCheck, OnChanges, OnDestroy,
+               OnInit {
+             @Input() value = 'foo';
+
+             ngAfterContentChecked() { this.log('AfterContentChecked'); }
+             ngAfterContentInit() { this.log('AfterContentInit'); }
+             ngAfterViewChecked() { this.log('AfterViewChecked'); }
+             ngAfterViewInit() { this.log('AfterViewInit'); }
+             ngDoCheck() { this.log('DoCheck'); }
+             ngOnChanges() { this.log('OnChanges'); }
+             ngOnDestroy() { this.log('OnDestroy'); }
+             ngOnInit() { this.log('OnInit'); }
+
+             private log(hook: string) { logs.push(`${hook}(${this.value})`); }
+           }
+
+           @NgModule({
+             declarations: [Ng2Component],
+             entryComponents: [Ng2Component],
+             imports: [BrowserModule],
+           })
+           class Ng2Module {
+             ngDoBootstrap() {}
+           }
+
+           const bootstrapFn = (extraProviders: StaticProvider[]) =>
+               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
+           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
+           const ng1Module =
+               angular.module('ng1', [lazyModuleName])
+                   .directive('ng2', downgradeComponent({component: Ng2Component, propagateDigest}))
+                   .run(($rootScope: angular.IRootScopeService) => {
+                     rootScope = $rootScope;
+                     rootScope.value = 'bar';
+                   });
+
+           const element =
+               html('<div><ng2 value="{{ value }}" ng-if="!hideNg2">Content</ng2></div>');
+           angular.bootstrap(element, [ng1Module.name]);
+
+           setTimeout(() => {    // Wait for the module to be bootstrapped.
+             setTimeout(() => {  // Wait for `$evalAsync()` to propagate inputs.
+               const button = element.querySelector('button') !;
+
+               // Once initialized.
+               expect(multiTrim(element.textContent)).toBe('bar Content');
+               expect(logs).toEqual([
+                 // `ngOnChanges()` call triggered directly through the `inputChanges` $watcher.
+                 'OnChanges(bar)',
+                 // Initial CD triggered directly through the `detectChanges()` or `inputChanges`
+                 // $watcher (for `propagateDigest` true/false respectively).
+                 'OnInit(bar)',
+                 'DoCheck(bar)',
+                 'AfterContentInit(bar)',
+                 'AfterContentChecked(bar)',
+                 'AfterViewInit(bar)',
+                 'AfterViewChecked(bar)',
+                 ...(propagateDigest ?
+                         [
+                           // CD triggered directly through the `detectChanges()` $watcher (2nd
+                           // $digest).
+                           'DoCheck(bar)',
+                           'AfterContentChecked(bar)',
+                           'AfterViewChecked(bar)',
+                         ] :
+                         []),
+                 // CD triggered due to entering/leaving the NgZone (in `downgradeFn()`).
+                 'DoCheck(bar)',
+                 'AfterContentChecked(bar)',
+                 'AfterViewChecked(bar)',
+               ]);
+               logs.length = 0;
+
+               // Change inputs and run `$digest`.
+               rootScope.$apply('value = "baz"');
+               expect(multiTrim(element.textContent)).toBe('baz Content');
+               expect(logs).toEqual([
+                 // `ngOnChanges()` call triggered directly through the `inputChanges` $watcher.
+                 'OnChanges(baz)',
+                 // `propagateDigest: true` (3 CD runs):
+                 //   - CD triggered due to entering/leaving the NgZone (in `inputChanges`
+                 //   $watcher).
+                 //   - CD triggered directly through the `detectChanges()` $watcher.
+                 //   - CD triggered due to entering/leaving the NgZone (in `detectChanges`
+                 //   $watcher).
+                 // `propagateDigest: false` (2 CD runs):
+                 //   - CD triggered directly through the `inputChanges` $watcher.
+                 //   - CD triggered due to entering/leaving the NgZone (in `inputChanges`
+                 //   $watcher).
+                 'DoCheck(baz)',
+                 'AfterContentChecked(baz)',
+                 'AfterViewChecked(baz)',
+                 'DoCheck(baz)',
+                 'AfterContentChecked(baz)',
+                 'AfterViewChecked(baz)',
+                 ...(propagateDigest ?
+                         [
+                           'DoCheck(baz)',
+                           'AfterContentChecked(baz)',
+                           'AfterViewChecked(baz)',
+                         ] :
+                         []),
+               ]);
+               logs.length = 0;
+
+               // Run `$digest` (without changing inputs).
+               rootScope.$digest();
+               expect(multiTrim(element.textContent)).toBe('baz Content');
+               expect(logs).toEqual(
+                   propagateDigest ?
+                       [
+                         // CD triggered directly through the `detectChanges()` $watcher.
+                         'DoCheck(baz)',
+                         'AfterContentChecked(baz)',
+                         'AfterViewChecked(baz)',
+                         // CD triggered due to entering/leaving the NgZone (in the above $watcher).
+                         'DoCheck(baz)',
+                         'AfterContentChecked(baz)',
+                         'AfterViewChecked(baz)',
+                       ] :
+                       []);
+               logs.length = 0;
+
+               // Trigger change detection (without changing inputs).
+               button.click();
+               expect(multiTrim(element.textContent)).toBe('qux Content');
+               expect(logs).toEqual([
+                 'DoCheck(qux)',
+                 'AfterContentChecked(qux)',
+                 'AfterViewChecked(qux)',
+               ]);
+               logs.length = 0;
+
+               // Destroy the component.
+               rootScope.$apply('hideNg2 = true');
+               expect(logs).toEqual([
+                 'OnDestroy(qux)',
+               ]);
+               logs.length = 0;
+             });
+           });
+         }));
+
+      it('should detach hostViews from the ApplicationRef once destroyed', async(() => {
+           let ng2Component: Ng2Component;
+
+           @Component({selector: 'ng2', template: ''})
+           class Ng2Component {
+             constructor(public appRef: ApplicationRef) {
+               ng2Component = this;
+               spyOn(appRef, 'attachView').and.callThrough();
+               spyOn(appRef, 'detachView').and.callThrough();
+             }
+           }
+
+           @NgModule({
+             declarations: [Ng2Component],
+             entryComponents: [Ng2Component],
+             imports: [BrowserModule],
+           })
+           class Ng2Module {
+             ngDoBootstrap() {}
+           }
+
+           const bootstrapFn = (extraProviders: StaticProvider[]) =>
+               platformBrowserDynamic(extraProviders).bootstrapModule(Ng2Module);
+           const lazyModuleName = downgradeModule<Ng2Module>(bootstrapFn);
+           const ng1Module =
+               angular.module('ng1', [lazyModuleName])
+                   .directive(
+                       'ng2', downgradeComponent({component: Ng2Component, propagateDigest}));
+
+           const element = html('<ng2 ng-if="!hideNg2"></ng2>');
+           const $injector = angular.bootstrap(element, [ng1Module.name]);
+           const $rootScope = $injector.get($ROOT_SCOPE) as angular.IRootScopeService;
+
+           setTimeout(() => {    // Wait for the module to be bootstrapped.
+             setTimeout(() => {  // Wait for the hostView to be attached (during the `$digest`).
+               const hostView: ViewRef =
+                   (ng2Component.appRef.attachView as jasmine.Spy).calls.mostRecent().args[0];
+
+               expect(hostView.destroyed).toBe(false);
+
+               $rootScope.$apply('hideNg2 = true');
+
+               expect(hostView.destroyed).toBe(true);
+               expect(ng2Component.appRef.detachView).toHaveBeenCalledWith(hostView);
+             });
+           });
+         }));
+
       it('should only retrieve the Angular zone once (and cache it for later use)',
          fakeAsync(() => {
            let count = 0;
diff --git a/packages/upgrade/test/static/test_helpers.ts b/packages/upgrade/test/static/test_helpers.ts
index a384f7e9cd..c1d12988b1 100644
--- a/packages/upgrade/test/static/test_helpers.ts
+++ b/packages/upgrade/test/static/test_helpers.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {PlatformRef, Type} from '@angular/core';
+import {NgZone, PlatformRef, Type} from '@angular/core';
 import * as angular from '@angular/upgrade/src/common/angular1';
 import {$ROOT_SCOPE} from '@angular/upgrade/src/common/constants';
 import {UpgradeModule} from '@angular/upgrade/static';
@@ -18,11 +18,19 @@ export function bootstrap(
   // We bootstrap the Angular module first; then when it is ready (async) we bootstrap the AngularJS
   // module on the bootstrap element (also ensuring that AngularJS errors will fail the test).
   return platform.bootstrapModule(Ng2Module).then(ref => {
+    const ngZone = ref.injector.get<NgZone>(NgZone);
     const upgrade = ref.injector.get(UpgradeModule);
     const failHardModule: any = ($provide: angular.IProvideService) => {
       $provide.value('$exceptionHandler', (err: any) => { throw err; });
     };
-    upgrade.bootstrap(element, [failHardModule, ng1Module.name]);
+
+    // The `bootstrap()` helper is used for convenience in tests, so that we don't have to inject
+    // and call `upgrade.bootstrap()` on every Angular module.
+    // In order to closer emulate what happens in real application, ensure AngularJS is bootstrapped
+    // inside the Angular zone.
+    //
+    ngZone.run(() => upgrade.bootstrap(element, [failHardModule, ng1Module.name]));
+
     return upgrade;
   });
 }