diff --git a/tools/plunker-builder/builder.js b/tools/plunker-builder/builder.js
index 033e6fee62..9189cc0cf9 100644
--- a/tools/plunker-builder/builder.js
+++ b/tools/plunker-builder/builder.js
@@ -9,7 +9,9 @@ var fs = require("fs");
 var globby = require('globby');
 var mkdirp = require('mkdirp');
 
-var indexHtmlTranslator = require('./indexHtmlTranslator');
+var fileTranslator = require('./translator/fileTranslator');
+var indexHtmlRules = require('./translator/rules/indexHtml');
+var systemjsConfigExtrasRules = require('./translator/rules/systemjsConfigExtras');
 var regionExtractor = require('../doc-shredder/regionExtractor');
 
 class PlunkerBuilder {
@@ -141,7 +143,7 @@ class PlunkerBuilder {
       }
 
       if (relativeFileName == 'index.html') {
-        content = indexHtmlTranslator.translate(content);
+        content = fileTranslator.translate(content, indexHtmlRules);
         if (config.description == null) {
           // set config.description to title from index.html
           var matches = /<title>(.*)<\/title>/.exec(content);
@@ -150,6 +152,11 @@ class PlunkerBuilder {
           }
         }
       }
+
+      if (relativeFileName == 'systemjs.config.extras.js') {
+        content = fileTranslator.translate(content, systemjsConfigExtrasRules);
+      }
+
       content = regionExtractor.removeDocTags(content, extn.substr(1));
 
       this.options.addField(postData, relativeFileName, content);
diff --git a/tools/plunker-builder/translator/fileTranslator.js b/tools/plunker-builder/translator/fileTranslator.js
new file mode 100644
index 0000000000..b4a050f80f
--- /dev/null
+++ b/tools/plunker-builder/translator/fileTranslator.js
@@ -0,0 +1,47 @@
+// var first_time = true; // DIAGNOSTIC
+
+function translate(html, rulesFile) {
+  rulesFile.rulesToApply.forEach(function(rxDatum) {
+    var rxRule = rulesFile.rules[rxDatum.pattern];
+    // rxFrom is a rexexp
+    var rxFrom = rxRule.from;
+    if (rxDatum.from) {
+      var from = rxDatum.from.replace('/', '\/');
+      var rxTemp = rxFrom.toString();
+      rxTemp = rxTemp.replace('%tag%', from);
+      rxFrom = rxFromString(rxTemp);
+    }
+    // rxTo is a string
+    var rxTo = rxRule.to;
+    if (rxDatum.to) {
+      var to = rxDatum.to;
+      to = Array.isArray(to) ? to : [to];
+      to = to.map(function (toItem) {
+        return rxTo.replace("%tag%", toItem);
+      });
+      rxTo = to.join("\n    ");
+    }
+
+    /* DIAGNOSTIC
+    if (first_time && rxDatum.pattern === 'zone_pkg') {
+      first_time = false;
+
+      console.log('zone_pkg');
+      console.log('  rxFrom: '+rxFrom);
+      console.log('  rxTo: '+rxTo);
+      console.log('  replace: ' + html.replace(rxFrom, rxTo ));
+    }
+    */
+    html = html.replace(rxFrom, rxTo );
+  });
+
+  return html;
+}
+
+function rxFromString(rxString) {
+  var rx = /^\/(.*)\/(.*)/;
+  var pieces = rx.exec(rxString);
+  return RegExp(pieces[1], pieces[2]);
+}
+
+module.exports = {translate: translate};
diff --git a/tools/plunker-builder/indexHtmlTranslator.js b/tools/plunker-builder/translator/rules/indexHtml.js
similarity index 70%
rename from tools/plunker-builder/indexHtmlTranslator.js
rename to tools/plunker-builder/translator/rules/indexHtml.js
index 254fdcc750..68263885d1 100644
--- a/tools/plunker-builder/indexHtmlTranslator.js
+++ b/tools/plunker-builder/translator/rules/indexHtml.js
@@ -1,8 +1,4 @@
-module.exports = {
-  translate: translate
-};
-
-var _rxRules = {
+var rules = {
   basehref: {
     from: /<base href=".*"[/]?>/,
     to: '<script>document.write(\'<base href="\' + document.location + \'" />\');</script>'
@@ -41,7 +37,7 @@ var _rxRules = {
   },
 };
 
-var _rxData = [
+var rulesToApply = [
   {
     pattern: 'basehref',
   },
@@ -113,49 +109,7 @@ var _rxData = [
   }
 ];
 
-
-// var first_time = true; // DIAGNOSTIC
-
-function translate(html) {
-  _rxData.forEach(function(rxDatum) {
-    var rxRule = _rxRules[rxDatum.pattern];
-    // rxFrom is a rexexp
-    var rxFrom = rxRule.from;
-    if (rxDatum.from) {
-      var from = rxDatum.from.replace('/', '\/');
-      var rxTemp = rxFrom.toString();
-      rxTemp = rxTemp.replace('%tag%', from);
-      rxFrom = rxFromString(rxTemp);
-    }
-    // rxTo is a string
-    var rxTo = rxRule.to;
-    if (rxDatum.to) {
-      var to = rxDatum.to;
-      to = Array.isArray(to) ? to : [to];
-      to = to.map(function (toItem) {
-        return rxTo.replace("%tag%", toItem);
-      });
-      rxTo = to.join("\n    ");
-    }
-
-    /* DIAGNOSTIC
-    if (first_time && rxDatum.pattern === 'zone_pkg') {
-      first_time = false;
-
-      console.log('zone_pkg');
-      console.log('  rxFrom: '+rxFrom);
-      console.log('  rxTo: '+rxTo);
-      console.log('  replace: ' + html.replace(rxFrom, rxTo ));
-    }
-    */
-    html = html.replace(rxFrom, rxTo );
-  });
-
-  return html;
-}
-
-function rxFromString(rxString) {
-  var rx = /^\/(.*)\/(.*)/;
-  var pieces = rx.exec(rxString);
-  return RegExp(pieces[1], pieces[2]);
-}
+module.exports = {
+  rules: rules,
+  rulesToApply: rulesToApply
+};
diff --git a/tools/plunker-builder/translator/rules/systemjsConfigExtras.js b/tools/plunker-builder/translator/rules/systemjsConfigExtras.js
new file mode 100644
index 0000000000..d774197eac
--- /dev/null
+++ b/tools/plunker-builder/translator/rules/systemjsConfigExtras.js
@@ -0,0 +1,24 @@
+var rules = {
+  system_extra_main: {
+    from: /main:\s*[\'|\"]index.js[\'|\"]/g,
+    to:   'main: "index.ts"'
+  },
+  system_extra_defaultExtension: {
+    from: /defaultExtension:\s*[\'|\"]js[\'|\"]/g,
+    to:   'defaultExtension: "ts"'
+  }
+};
+
+var rulesToApply = [
+  {
+    pattern: 'system_extra_main'
+  },
+  {
+    pattern: 'system_extra_defaultExtension'
+  }
+];
+
+module.exports = {
+  rules: rules,
+  rulesToApply: rulesToApply
+};