Dragon's Keep was first developed for the Apple II in 1982 by Sunnyside Soft, the small developer established by Al Lowe and friends, prior to their meeting with Ken and Roberta Williams at Applefest 1982 where they sold the game at a small stand in ziplock baggies. The Sunnyside Soft release is extremely hard to find - a collector's item of the highest degree.
Ken and Roberta, noticing how similar the game looked to their own Hi-Res Adventures proposed to rerelease Dragon's Keep through Sierra. They left the code untouched but added a game map and stickers to the box for easier navigation and to enable kids to mark where the trapped animals are located by placing the stickers on the map.
Sierra also converted the game for the Atari 400/800, the Commodore 64 and the IBM PC/PC Jr.
