In a nutshell, DeePsea (formerly DeeP97) is a native 32-bit Windows program for creating DOOM style levels. Prior DeeP is a 32-bit DOS DPMI program for editing DOOM, DOOM II, Ultimate DOOM, BOOM, ZDOOM (and other DOOM ports), Heretic, Hexen, or Strife levels with Power, Speed and Ease. The powerful interactive WYSIWYG drawing tools, cut, paste and undo are just some of the features everyone dreams about. It supports keyboard and mouse commands and even lets you draw on wall textures!
DeePsea makes level editing easy for beginners and lets experts concentrate on creating high quality levels.
Lots of stuff you won't find anywhere else. The level checker is outstanding with many unique checks, such as a texture check for moving areas. It will catch many mistakes created by other editors, such as vertices with duplicate coordinates, one or more LineDefs in the same location or just "junk". DeePsea has unique BOOM LineDef<->LineDef tag checking.
You'll find a wealth of built-in graphics manipulation tools, including the ability to create brand new Texture Names, Flats or Sprites! Much faster and more efficient than Wintex, NWT or any other WAD manipulation tool in the world. This is especially useful for BOOM modified ports where these elements are even easier to use. Use you favorite Graphics tool (such as PSP) and import them right into your level.
DeePsea has a complete clipboard (no quick hacks here), an ultra-fast programmable nodes builder, and rapid redraw speed. You also get the power and ease of DeePsea's 3D level preview system that lets you look and MODIFY your DOOM map from any perspective before you play it!
DeePsea has all of the tools you need to create levels quickly, including drawing utilities, texture conversions from one game to another and Autocad style zoom functions. DeePsea's full function clipboard lets you cut, copy, paste, and mirror -- even between levels! With few exceptions, there is no reason to use a third party program.