Produced by: Jonathan Rimmer
Website: UWE Homepage
Releases:
* Ultima Underworld Editor (156.7 KiB, 64 hits)
* UWE Source (2.6 KiB, 37 hits)
* DPMI Memory Manager (40.5 KiB, 38 hits)

A 2D, DOS-based editor for both Ultima Underworld and Ultima Underworld 2. Also available is the source code. The program may require the DPMI Memory Manager because of the Allegro libraries that were used in its making.

Produced by: Peroxide/Telemachos
Websites: UGCK and Viewer
Releases:
* Underworld Viewer (84.8 KiB, 51 hits)
* Underworld Game Creation Kit (20.2 MiB, 54 hits)

Although Peroxide has ceased to be, some of their old projects are still kicking around on the Internet. The Underworld Viewer is a simple utility that renders all the levels of both Ultima Underworld and Ultima Underworld 2 using whichever acceleration mode you prefer so that you can view them and wander through them. It may also be possible to load the level models into a 3D rendering program, if the images on Peroxide’s site are any indication.

And Telemachos, formerly of Peroxide, never seems to run out of ways to keep busy. Building off of the Underworld Viewer, he produced an actual editing kit with which to edit different aspects of Ultima Underworld, as well as walk through all the levels and (possibly, if the screenshots tell the truth) test-play them.