ZETH

ZETH, by Randy Heit, is a revised version of DETH, and as such it is also compatible with Doom, Doom 2, Heretic and Hexen. ZETH has been programmed to include extensions to the Doom engine introduced by ZDoom.

Since ZETH 4.17 had been published at a time when ZDoom was at version 1.23 beta 33, it is a bit quirky, in that it will unceremoniously delete any newer text lumps introduced since then, like DECORATE, KEYCONF, DEHACKED, TERRAIN, etc. if present, when a ZDoom specific level is saved. However, it will leave the five original Hexen lumps, like MAPINFO, ANIMDEFS, SNDINFO, SNDSEQ and BEHAVIOR, intact.

So, if you want to use ZETH, finish the map first and then, when all the layout and playability is tested and polished, add the newer lumps with a utility like XWE.

Once understood, it may become your level editor of choice. Its clean interface is second to none.