This newly-released utility is a Windows-based utility is, at present, a nearly full-fledged editor for the first Ultima Underworld game. It allows players to fully edit all nine levels of the Stygian Abyss, to the point that nine brand new levels could in fact be created. A conversation editor is also included, and the utility supports importing custom textures and sprites as well. String and object data in the game can also be modified, enabling users to modify mantras, add new scrolls and books, and modify monster statistics (among other things).

Some hard-coded features of the game cannot be changed at this time, however; the player always starts in the same place on the first level of the Abyss, for example. The mana drain on the seventh level, and the shaking and health drain on the ninth level, are also unavoidable. Certain puzzles in the game are also not able to be modified, and some conversation features are missing.

You can grab a copy of the Ultima Underworld Editor from the project entry here at the Codex, or via the project’s Reddit post. At either place, links to videos explaining the use of the Editor can also be found.

(Hat tip: Ceearrbee)