This codebase was announced by Tom Ritter at the EKO security conference, and was actually used to factor a 512-bit RSA key in two days.
Greg, is there anything that NFS@Home can use in here?
(the GNFS subdirectory has some nice statistical visualizations too)
PS: The slides mention a service that factors 512-bit RSA keys at EUR5000 each. He's probably talking about
these guys.