MegaZeux

MegaZeux, or MZX, is a game creation system (GCS) inspired by Tim Sweeney/Epic Megagames' classic shareware game ZZT. MegaZeux was created in late 1994 by Gregory Janson, who formed her 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.

MZX was originally a DOS program, but is now licensed under the GNU GPL and is officially supported on Windows (Win95 and higher), Linux, Mac OS X, Wii, GP2X, PSP, and the DS, but has been ported to other platforms such as AmigaOS 4, OpenBSD, FreeBSD, OpenSolaris, Haiku and Android.