I am actually only vaguely familiar and I was wondering about that every time I saw the format referenced but never bothered to check, your comment is informative!
Yeah, I'm a long time user/disciple of https://zim-wiki.org ; it was basically Obsidian but 15-20 years early. To do some of the things that are now trivially easy with Obsidian I learned scripting and such, so I'm familiar with this very weird coincidence/name collision.
