Is GCL "abandoned" or "finished"? And how does it relate to CLISP, which is also part of GNU?
The last commit happened three months ago, so it's not exactly abandoned, but it could use more attention.
There's no relation to CLISP. There's a brief history on the home page; it started out as Kyoto Common Lisp in '84, then William Schelter took it up to support his work on GNU Maxima.
I did not realize updates were still being made to the source code, I thought the latest "release" on the website was from 2014.