An "AI Group" including Marvin Minsky (the director), John McCarthy (inventor of Lisp) and a talented community of computer programmers was incorporated into the newly formed Project MAC. It was interested principally in the problems of vision, mechanical motion and manipulation, and language, which they view as the keys to more intelligent machines. In the 1960s and 1970s the AI Group shared a computer room with a computer (initially a PDP-6, and later a PDP-10) for which they built a time-sharing operating system called Incompatible Timesharing System (ITS).