If you checked the link Kano put in just above, it explains it. The code for the pool and database are open source. As Kano said, anyone who's reasonably technically apt could use the code to build a simple pool. That's what open source is about. However...it's no guarantee the person applying the code really does know what they're doing... 

BTW...not that I'm intimating that the "new" site is nefarious...but I generally don't go tiptoeing around questionable sites just to see wassup. Good way to catch something you can't get rid of.