I love this mini article, however, I disagree with the main conclusion that collaborative editing is not an algorithmic but a UI/UX problem. I think that collaborative editing is a semantic problem. To the best of my knowledge (I'm writing this comment without much preparation), all SVN/Git algorithms are based on UNIX diff (Hunt–Szymanski algorithm). UNIX diff (and patch) is purely syntax driven.

Actually, I will make a small deviation here: I think it is a big industry/startup/open source project there, in creating a set of semantic diff algorithms/implementations. For example, due to my present job, I am very interested in collaborative editing of electrical circuits, and layouts for PCB and chips. Altium and KiCad are trying, for exmaple, to store everything in XML/text files and put the text files in Git/SVN and I can tell you a botched C++ program is nothing in comparison to a botched and malformed electrical circuit. So we need diff tools that "know" about a text file, vs rich-text with formatting, vs bitmap vs vector image, vs song, vs English text. Anybody want to start an open source project (DM me or put a comment here).

Anyhow, thanks to the authors on the great insights and let's work on the take home!