AGI, or the Adventure Game Interpreter, was developed by Sierra Online for the development and release of their games in the late 1980's. Originally released for the PCjr to take advantage of it's new features, it was later ported to many other systems like the PC, Amiga and Macintosh. Sierra was hailed for creating "3D" games, which meant the player could move their character around the screen and behind objects. Games using the interpreter have very distinctive blocky graphics and a text parser interface where the player could type in their commands. Players on the PC could control their characters using the keyboard or the joystick while other systems also had mouse support.