> Solaris, meanwhile, which had long been available on x86, saw its “own” ISA SPARC live on in the server space until roughly 2017 or so, and was even briefly available as open source until Oracle did its thing.

Maybe worth noting that SPARC was (is?) licensable:

* https://sparc.org

OpenSPARC is under GPL2.

* https://news.ycombinator.com/item?id=12578083