From Wikipedia:
Ready at Dawn is a video game developer located in Irvine, California and is composed of some former members of Naughty Dog and Blizzard Entertainment. Formed in 2003, they released their first title, Daxter, to critical acclaim for the Sony PlayStation Portable.
Ready at Dawn finished working on their second PSP title, God of War: Chains of Olympus as well as a Wii version of Ōkami, with added motion controls. In June 2008 it was confirmed that the company have finished developing titles for the PSP, and that they have returned the relevant development kits to Sony. However, reports claim that the developer received new development kits after returning. They are currently developing God of War: Ghost of Sparta collaberatively with Sony's Santa Monica Studio for the PSP and PSPgo, with their new proprietary engine.