Simutronics is an American online games company whose products include GemStone IV and DragonRealms.

It was founded in 1987 by David Whatley, with husband and wife Tom & Susan Zelinski.

GemStone was originally accessed through General Electric's internet service provider GEnie, later becoming accessible through AOL, Prodigy, and CompuServe before Simutronics finally moved all their games to their own domain in 1997.

HeroEngine is a 3D game engine and server technology platform developed specifically for building MMO-style games, based around a system similar to the IFE using the Hero Script Language (HSL).

[12] Simutronics sold the HeroEngine to Idea Fabrik, Plc.