RAC used to stand for "Remix Artist Collective". That name doesn't make much sense anymore. Who cares?
These days it's the solo project of André Allen Anjos.
RAC is primarily known for remixes (200+). Check them out here. It started with an ambitious goal to change the way things were remixed. Taking the focus away from danceability and attempting different and interesting arrangements. Some notable examples include: U2, Lady Ga Ga, Bob Marley, Ella Fitzgerald, Kings Of Leon, Katy Perry, The Shins, Bloc Party, Chromeo, Lana Del Rey, Two Door Cinema Club and many many more.