, officially abbreviated MPO, is an action-adventure stealth video game directed by Masahiro Yamamoto and written by Gakuto Mikumo, with series creator Hideo Kojima acting as a producer. Portable Ops was developed by Kojima Productions and published by Konami in 2006 for the PlayStation Portable (PSP). Metal Gear Solid: Portable Ops Plus (officially abbreviated MPO+), the game's stand-alone expansion focused primarily on online play, was released for the PSP in 2007–08.