After all these years, it looks like Red Hat is still a bit scared to distribute THE NEEDFUL to play a DVD Video. After merely scooping a libdvdcss RPM from this cool guy's repository (the CentOS 8 RPM installed without issue on Rocky Linux 9), VLC instantly gained the ability to play DVDs. I could not find any other obvious source of the library for this operating system.
Rocky Linux 9 & HP Elitebook 8470p: GPU problems irreconciled
Rocky Linux 9 had poor graphical performance on my HP EliteBook 8470p laptop. On investigation, it was using the "llvmpipe" Mesa backend, because it lacked ati_drv.so (from “xf86-video-ati”,) for the AMD Radeon HD 7570M GPU; backporting[?] that package from Rocky Linux 8 then rebooting left Steam not finding r600_dri.so (though it seems to have fixed hardware acceleration for Firefox/etc.); scooping up that library from the Rocky Linux Stream 8 …