EasyToon (from 1998, I believe, built for Windows 95) runs on Windows 11. One of my favorite pieces of software.

It's a thing for making little black and white animations. (With GIF export.)

It was popular in the early 2000s and there was a subculture around it on animation forums.

English version (hey, still online!):

https://www.superfundungeonrun.com/easytoon/

Original version (Japanese, w/ screenshots):

https://web.archive.org/web/20020111185602/http://www.radium...

There's also a forked version on a French website (also available in English) with some extra features. But I like to keep it simple :)

https://www.flat2d.com/easytoon.html