SunDog: Frozen Legacy is a 1984 space trading and combat simulator video game. SunDog was first developed for the Apple II, with version 1.0 being released in March 1984, and version 1.1 (bug fixes) released three weeks later. Version 2.0, which included enhancements and improved performance, was released in October, 1984. A greatly enhanced version was released for the Atari ST in December 1985. Although FTL intended to release further games in the series, this was pre-empted by the tremendous success of their follow-on effort, Dungeon Master.

The first game produced by FTL Games, and the only game programmed by Bruce Webster, SunDog not only stored an impressive amount of data in the limited 64K of the Apple II, it also implemented a GUI inspired by the pioneering interface developed at Xerox PARC.[