WADED

WADED is a DOS-based editor written by Matthew Ayres.

WADED was one of the first line-based level editors. One of the other good features of WADED is that all things placed on the map are given an icon. WADED was also one of the first editors to support Heretic.

It was Matthias Worch's first level editor. You can see him editing it here at 6:45 into the movie.