Vendetta Online is a twitch-based, science fiction massively multiplayer online role-playing game (MMORPG) developed by Guild Software for the operating systems Android, Linux, Mac OS X, iOS, and Microsoft Windows. It uses the NAOS game engine, a fully real-time flight model and combat system, to offer first-person/third-person shooter-style player versus player and player versus environment battle action against the backdrop of a massively multiplayer universe. Vendetta Online shipped as a commercial MMORPG on November 1, 2004 with a subscription-based business model, although it has been running continuously since April 2002. Vendetta Online is available to play across a wide array of platforms, including the Oculus Rift virtual reality display, allowing all users to directly interact in