PrimeGrid The sieves have been Mac'd out!

[Free-DC]

321, PPS, and PSP sieves now have application support for Mac OS X 10.4 running on Intel and 10.5 running on 64bit Intel. PPS sieve also offers application support for Mac OS X 10.3 running on PPC.

More... (http://www.primegrid.com/forum_thread.php?id=2456)