MegaZeux, or MZX, is a game creation system (GCS) based on Tim Sweeney/Epic Megagames' classic shareware game ZZT. MegaZeux was created in late 1994 by Gregory Janson, who formed his own company, Software Visions (now defunct). Like ZZT, MZX was originally released as shareware and the world editor portion of the program was included for free, allowing third parties to create their own worlds without even registering.