From HN a few days ago: https://github.com/microsoft/Garnet

A Microsoft Research, open source, performant, almost RESP compatible alternative (according to them)

There is also Valkey, a fork from just before the change backed by AWS, Google, Oracle who are paying a few former core devs

https://github.com/valkey-io/valkey

And not to forget Redict, also a fork, that is maintained by drew devault

https://codeberg.org/redict/redict