Add a section discussing how people can continue to use their own DVCS if they

so choose.

pep-0374.txt

@@ -118,8 +118,6 @@ DVCS:
 * git : http://book.git-scm.com/1_the_git_object_model.html
 
 
-
-
 branch
     A line of development; a collection of revisions, ordered by
     time.
@@ -222,6 +220,24 @@ significant performance problems which seem unlikely to be addressed
 in the near future.
 
 
+Interoperability
+================
+
+For those who have already decided which DVCSs they want to use, and
+are willing to maintain local mirrors themselves, all three DVCSs
+support interchange via the git "fast-import" changeset format.  git
+does so natively, of course, and native support for Bazaar is under
+active development, and getting good early reviews as of mid-February
+2009.  Mercurial has idiosyncratic support for importing via its *hg
+convert* command, and `third-party fast-import support`_ is available
+for exporting.  Also, the Tailor_ tool supports automatic maintenance
+of mirrors based on an official repository in any of the candidate
+formats with a local mirror in any format.
+
+.. _third-party fast-import support: http://repo.or.cz/r/fast-export.git/.git/description
+.. _Tailor: http://progetti.arstecnica.it/tailor/
+
+
 Usage Scenarios
 ===============