Atarisoft was a game publisher that released Cantipede, Defender, and Pac-Man for the Intellivision. Pac-Man is the only game to be released first by INTV Corporation under license and then directly by publisher (meaning two boxes and in-game title screens exist for same game code).
Source Links:
intellivision.fandom.com/wiki/Atarisoft
www.intvfunhouse.com/games/pac.php