In the beginning, there was ZZT. ZZT was a set of little shareware games for DOS that used VGA text mode for all the graphics, leading to such whimsical Rogue-like choices as
ä for ammo pickups,
Ω for lions, and
♀ for keys. It also came with an editor, including a small programming language for creating totally custom objects, which gave it the status of “game creation system” and a legacy that survives even today.
A little later on, there was MegaZeux. MegaZeux was something of a spiritual successor to ZZT, created by (as I understand it) someone well-known for her creative abuse of ZZT’s limitations. It added quite a few bells and whistles, most significantly a built-in font editor, which let aspiring developers draw simple sprites rather than rely on whatever they could scrounge from the DOS font.
And then, nothing. MegaZeux was updated for quite a while, and (unlike ZZT) has even been ported to SDL so it can actually run on modern operating systems. But there was never a third entry in this series, another engine worthy of calling these its predecessors.
I think that’s a shame.