Dexter released the puzzle game Xod quite a while ago (April 1999). Decent ZZT puzzlers are hard to find... Xod is one of them. It was released under the Reptile House banner.
Xod is the big daddy of Dexter's BoulderXod game(s), which were released later on. The game consists of three puzzle mini-games: BoulderXod, TuneXod and QuizXod.
BoulderXod is a Sokoban-like game for ZZT, which means you have to push boulders onto templates in order to finish the levels. If you've ever played Sokoban (or a game similar to it) and liked it, you can be pretty sure you'll find this enjoyable, too.
TuneXod is the music puzzler of the game. You'll hear an object pumping out some tunes and you have to guess what notes they are. Of course, a lil' tutorial is recommended.
The last mini-game is QuizXod, which exists of a bunch of multiple choice questions. It's not really puzzling, but it's quite fun to do, really.
Overall, Xod is an enjoyable puzzle game with some good graphics and funky music.