> CCL, as far as I can tell, is abandonware

Last release was August 14 2024. For a 30+ year old project, that's quite recent methinks.

It clearly doesn't move as fast as SBCL, but I wouldn't call it abandoned either.

ototh, afaiu, SBCL gave up on ARM32. Can't blame them for that, but until 2023 I was still using an early Banana Pi with such. CCL worked there much better (also it's GC seems more robust).