I am occasionally folding on my linux machine. Using the Core17 and client-type beta flags seems to have finally got it working for linux machines. I tried it last year but since then PG has made some improvements in their client. I'm supposed to get at least 12000ppd if I fold 24/7, but I only let the machine run up to 12 hours a day folding. It also seems that GPU folding makes everything a bit laggy, so I can't let it run when it's used for web surfing. I stopped using the CPU for folding since it got too loud and didn't seem as efficient for the part-time folding I do.
Core17, Project 8900 = 6000 base credit; ~27 hours to complete
Estimated PPD (24/7)= 12273
AMD Phenom II 1045T
NZXT Hale 650W PSU
Antec 302 (2x120mm intakes + 140mm & 120mm exhausts)