Variant mapping of source code

I had an idea a little while back that keeps coming up in my thoughts, and that's variant mapping.

For example, Anaphraseus is a translation tool similar to TRADOS's Word-native libraries, but it's written for OpenOffice. I want to use it in Word, though, so I thought it would be nice (see) to write a cross-parser that would create a converted Word-native Basic variant. As updates arise for the OO.o version, you'd keep running the converter, and if you made changes on the Word side, you'd back-convert to put your changes into the master. Obviously, to a certain extent this would be inherently lossy (some changes wouldn't make it back), but if done carefully, it should work.

Then I ran across the ongoing drama about forking reddit open-source and realized this is the same kind of thing. Reddit's license for forks requires detailed documentation of all differences between the original and the fork, which an automated system would be able to do.

Just a thought. Even if it only managed to auto-convert some portion of changes to one end or the other and could flag the rest, it would be a useful tool.