But the point I want to make is that, you've heard me say it before, I think that the sync/async collaboration, the differential versioned filesytem, and the undo stack, is really the same issue. If you can make a network protocol that does three-way diffs using the same data that is in the versioned filesystem, and keeps XML compliant to the DTD, anyone can use it for any data and they get versioning, collaboration, and undo/redo for free and sugar rules the world. Homunq 06:06, 3 April 2009 (UTC)