I used it fairly recently to play with maps generated by Angdoom, so I am fairly confident that it still works. For a somewhat restricted definition of "works", anyhow ;-) If you try LDE and run into any problems, drop me an email.
Screenshots at quarter size, click for full.
Full screen shot of my LDE setup
Screen shot of console
Screen shot of edit window in THING mode
Screen shot of edit window in WALL mode (selecting a wall texture)
Screen shot of edit window in SECTOR mode (selecitng a floor texture)
Screen shot of edit window in VERTEX mode
