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