Bob Mixon pointed out MoonEdit on his blog.

Had an hour of fun with this application.

I think it has a lot of potential. Technology similar to this is something I would prefer to have in the next version of Visual Studio (I havent checked out 2005 or Team System yet). But imagine the new twist this capability will give to Pair Programming. Ok Pair Programming might not have been the best example. but there would naturually be quite a productivity boom by 'peer-to-peer-ifying' collaborative application development. You would no longer have to wait till someone checks-in a class to do your changes to it. It would be possible for more than one individual to collaboratively build a single file of code.

This kinda technology is also somethnig I would like to see in the next office system and SharePoint. The current webdiscussion system is sattisfactory but not as great as this. When a document is spawned to a document workspace, editing that document should bring about collaboration features like present in MoonEdit (i.e. in addition to Web Discussions).

It would give real meaning to collaboration.