Ratpoison was always my favourite tiling window manager. There's also a fork called sdorfehs[0] which seems to still be maintained and has a bunch of minor improvements here and there.

0. https://github.com/jcs/sdorfehs

It was released 25 years and four days ago, and is still around. Simple enough to still work I'd bet, though the last official release was in 2017 or so.

https://www.nongnu.org/ratpoison/

http://savannah.nongnu.org/projects/ratpoison

I used it for a while back then, before switching to IceWM because it was more fun to configure. Prepared me well for a much later move to i3.

A quick google search reveals a lot of (4 years old) youtube videos about it. And although not very meaningful, it's archwiki page was updated a lot in the past 4 years, which means there are still people visiting that page and potentially using it. I've also seen some recent ratpoison rices on the internet.

For support, I'm sure the users in the past has generated enough forum threads for you.

Ratpoison seems like one of those pieces of software that you can release without it bitrotting. The manpage also was very comprehensive from what I remember, though I haven't used Ratpoison in a number of years. I wouldn't worry about it breaking or being hard to understand.

IIRC StumpWM authors thought of it as a [ideological] successor of ratpoison, no?

Shawn Betts, the driving force behind StumpWM was also one of the primary developers of ratpoison, according to Wikipedia: <https://en.wikipedia.org/wiki/Ratpoison>