From Halopedia, the Halo wiki
Damian Isla is a video game programmer and video game engineer. Isla was hired at Bungie Studios in 2004 to write the AI script for Halo 2. Thus, he was credited as an engineer on the Halo 2 project. He worked at Bungie for the duration of Halo 3, and left the studio in late 2008 to move back to Boston where he founded the independent games company Moonshot Games.