Pathfinder?

Yeah. It's a variation of Dungeons & Dragons 3.5 edition. Most people universally think that D&D 4.0 tried to be an MMO too much because of how much customization was lost in the version up.

So the folks over at Paizo took the 3.5 rules and streamlined them, fixed a lot of the balance issues and marketed the new rule set as "Pathfinder".

So, basically, D&D.