I've always found that if anyone ever mentions any piece of software, Onyx or Pacifist, or PithHelmet or whatever I just type it into google and I am presented with about 20 places to download it.
And in the search for Mac software you're much safer to just stick with VersionTracker and Mac OS X Downloads. You'll find 99% of all (mostly harmless) OS X software on one (or both) of those sites...