So according to LWN.net, Rocky Linux 8.4 reached General Available (GA). This is great as it means that there are two* 'community rebuild' to move CentOS 8 systems to if CentOS Stream is not a good match.
Alma is built by the same people who have built Cloud Linux for years. From their downloads they focusing on x86_64 which is the most common in the cloud.
Rocky Linux was founded by a person who worked on the pre-CentOS project of ChaOS. The wikipedia article on Rocky covers in more detail than me regurgitating it. My main reason for looking at it, is that it has a ARM port which will eventually run nicely on a raspberry pi for people interested in it.
My other reason was to remind people that if they are using CentOS Linux, that the end of life for 8 is December 31, 2021. Before that time it would be good to look at switching to Alma, CentOS Stream 8, Oracle Linux, Red Hat Enterprise Linux, or Rocky. These transitions take time, and there are only ~190 days before it needs to be done.
[*] There is a third rebuild which has been around for years called Springfield Linux made at Princeton University. However either due to the pandemic or other items, it does not seem to have had regular updates.