I think it’s a great idea. Trackers have always been about collab/sharing stuff. But forget about the clipboard copy/paste stuff, nobody will bother doing that, you’ll loose the overview etc.
Instead, it could be made to work as a service, completely transparent and in realtime. This would simply take it to the next level. But anyone with the wish to start developing something like this should probably wait for the Renoise scripting API to become available. Scripted network access has already been tested as a proof of concept, and the rest is a matter of updating song data, for which there’s full access.
However, this is only the client part. From a technical viewpoint, it would probably be a good idea to have a central server on the internet (a “tracker” that will monitor all the clients. This would reduce the traffic needed to have everybody synced to each other, and help to identify and resolve conflicts between versions.
I’m thinking about the challenges that every other piece of realtime collaboration software has to address, stuff like resolving conflicting user edits, ability to rollback to a previous version if someone deletes the whole project etc.
Wikipedia has an article which describe this dilemma:
All in all, I would say that this is a very interesting idea, but also a very complex one to realize.