In response to the release of 4th Edition Dungeons & Dragons, Paizo Publishing released a series of books using a slightly modified 3.5 system they call Pathfinder. They retooled the core classes and races, changed how some game mechanics work(for instance, magic item creation now no longer requires experience), changed around some of the core feats and how they work, added new feats, and generally changed things around in order to balance things better. All of it is compatible with any 3.5 books you may have with very little conversion necessary.

I've been playing in a PF campaign lately and it seems to be pretty good, there isn't much change in the basic feel of things so far but as time goes on and we get to higher levels I'm sure I'll notice it more. Just from reading the books, however, a lot of the changes have made things more powerful or versatile. The only problems I have is that Wizards and Clerics are still ridiculously powerful(even by the Pathfinder standards) by the end of the game, and there still isn't a counterbalance for that. That and it's basically a well-presented set of houserules taken to the extreme, and while I LIKE them I don't think all of it works.

So, those of you that have looked into this, what are your opinions on it?