Halo 3: ODST 2009 first-person shooter sport developed by Bungie. Published by Microsoft Game Studios. The fifth installment in the Halo franchise as a side game,[1] it was launched on the Xbox 360 in September 2009. Players assume the roles of United Nations Space Command Marines, generally known as "Orbital Drop Shock Troopers" or ODSTs, throughout and after the occasions of Halo 2.