World Community Grid at https://www.worldcommunitygrid.org/ is also running, though it has had struggles since moving datacenters, and it seems their external stats are still out of commission.

I've recently decided to end my own participation, mainly because I've run three systems into the ground, and we're now in the "save what you can" era. There's one motherboard I want to get refurbished, since it became unstable when idle but loved 24x7 crunching. It would make a great NAS if I could find some DDR4 at a price I could stomach, or I could lay it in as a spare if the new motherboard goes south in the future.