RAC is short for Remix Artist Collective. If you search for music as often as I do, you'll run into these RAC remixes all the time. It's actually pretty cool how they do this shit. There are three guys, one in NYC, one in Portugal, and one in the Netherlands. All have their own sound, but release the music under one name.
Below are two good tracks. The first, a take on the TPC track "Be Good," the second is Ra Ra Riot's "Boy."