Star Citizen is an upcoming space trading and combat simulator video game for the PC Platform. Star Citizen will consist of two main elements: a persistent world massively multiplayer online game mixing elements of 1st person space combat and interstellar trade (known as Star Citizen) and a branching single-player and drop-in co-operative multiplayer campaign (known as Squadron 42), together with customizable private server components. (Source: Wikipedia)
Star Citizen is currently in development with an estimated release date in Q4 2014. Star Citizen is being entirely crowd funded.