Building from source should work on linux. I'm still ironing out a lot of the kinks, the search window going blank is at the top of my list and I am also working on editor reliability.
Hope you can get the full value out of this once I've made it more reliable!
The main reason I built mmap is I started a new job a few months ago which required learning a ton of new workflows that leveraged a bunch of unfamiliar technologies. Documentation for these was scattered over github, confluence, google groups, etc. which made it both time consuming and difficult to find what I was looking for.
I wanted to be able to save documentation and code snippets in my own words so I could quickly find it without switching windows. It's lead to a noticeable jump in my productivity so far.