I'm looking for a Wiki with excellent concurrency support where multiple users may edit a page at the same time. Are there any?
We currently use cvstrac where one user may edit one wikipage at a time. If two users edit the same page and user A saves the page first, followed by user B. Then user B's version will be used and A will be in the page version history.
It would be nice with a wiki which is a bit more modern. In Google Docs for example multiple users editing the same document at the same time works great. But we want it as a wiki, which we host our self's.
Ideally it would be free software and work in Ubuntu GNU/Linux. It would also be possible to create a plugin to it, which marks all #nnnn where nnnn is a decimal number as a special link (to our bug tracking software). But concurrency is key!