Awesome
ZZT.js
This is an attempt to recreate a ZZT engine in HTML5/JS.
ZZT is a game developed in 1991 by Tim Sweeney of Potomac Computer Systems, which most people would probably recognize today as Epic Games.
ZZT, despite the dated (even for 1991) textmode graphics, was notable for being one of the first games to have a built-in editor and a specialized scripting language (ZZT-OOP) that made it very easy for users to develop their own game worlds. A large community sprung up around ZZT development.
ZZT was sufficiently popular to finance Sweeney's next game, Jill of the Jungle, and successive games which would eventually lead to the gaming powerhouse that Epic is today. Many members of the ZZT community would also move on to become professional game designers in their own right.
In 1998, as the game became increasingly obsolete, Sweeney released ZZT (and the four shareware game worlds) for free. Unfortunately, the source code was long since lost, hampering any development past ZZT 3.2. However, the ZZT community has reverse-engineered many aspects of the game, allowing for alternative editors and alternative engines to exist.
(As for my part, this project is an exercise in learning HTML5 and JavaScript while on vacation from work, where the programming I do is considerably more low-level. ZZT's engine is simple enough and the formats are well-known, so I expect it won't take too long to come up with something workable...)