Seventeen or Bust is a non-BOINC DC project that has been a part of the DC-Vault for many years. It used the Prime95 client just like the CPU version of GIMPS. Recently their site went down and the admin has not chimed in. However, there is a thread at PrimeGrid with a few updates indicating the entire server including backups have been lost. There is no telling if it will return just yet. So, there is currently a removal thread at DC-Vault where people can discuss the issue. For those not aware, PrimeGrid also runs SOB work but it is different ranges. They have worked with Louie in the past so that the "science" doesn't over lap.
http://www.team-ninja.com/vbulletin/showthread.php?t=58370
http://www.team-ninja.com/vbulletin/showthread.php?t=58370