Wad Editor
Latest Version: 1.16 (2009.05.05)
Developed by Csabo
What's Bad

No instructions or manual, other than this list.
No Undo. (To get around this, run the map often. This compiles and saves the map. If something goes wrong, just don't save.)
Not for beginners. You should know the basics of Doom level editing.
Won't highlight lines/sectors that are tagged.
Other bugs (probably).

What's Good

Copy/Paste implemented. Select anything then press CTRL+V.
Dragging lines and sectors works well.
Added XWE Script to the map editor. Press SHIFT+R to run a script.
Uses ZenNode to build nodes.
Handles Doom and ZDoom format maps. You can even switch from a Doom format to a ZDoom format without converting (and vica versa).
Switch configuration on the fly (e.g. Doom/Doom2/ZDoom or create your own).
Error checking and fixing.
Quick zoom with +/- or point somewhere and press Z. Almost unlimited zoom in magnification.
Grid on/off, grid increase with Shift +/Shift -.
Mouse drag to select an area, mouse drag and press Control to add/remove from the selection.
Draw mode (D) with line automatic line splitting.
Draw new sector mode (SHIFT D), maintains sector integrity as long as no linedefs are crossed.
One-key (R) compile and run feature, easy to test levels.
Show linedef lengths mode. (SHIFT+L)
Fake 3D preview mode.
Thing, Linedefs, Sectors and Vertex modes select only that type of objects.
All mode selects whatever you point to.
Easily set any property for multiple selections.
When changing properties (e.g. sector ceiling height) ++number will work the same way as in WadAuthor.

XWE in action - E1M1
XWE in Doom mode
Click for larger image

XWE in action - Darkest Hour Map01
XWE in ZDoom mode
Click for larger image