I'm extensively using real-time collaborative edition for TeX/LaTeX documents.

Today, this usage is dominated by Overleaf/Sharelatex which are both somehow proprietary.

Yesterday, there was bluelatex (full disclosure: I was one of the author, together with @tdurieux and @satabin), but the project has stalled, in particular because of serious bugs / limitations in the synchronization.

It would be great to have collaborative edition for TeX/LaTeX documents coming again in the free world, and having Tandem support in a Linux TeX/LaTeX editor (eg TeXWorks) would be a solution!