Ok... I tried searching in the forum and couldn't find the answer. I apologize if the following question as been made before.
I had an original Duke Nukem edition back in 1997 (not the plutonium pack/atomic edition which came later), and I remember tweaking and playing with it's original files using the "mod" tools that were bundled with the game. The file was called "Goodies" if I'm not mistaken.
It allowed a lot of Total Conversions (TCs) to be made, way before Half-life and subsequent "MODs" =)
So, my question is if this tools: Build, Editart, Kextract, etc. are present in the "GOG's edition"?

If anyone knows about the legal stuff regarding the Goodies folder, let me know.
I'll get that uploaded pronto if it's not under copyright.

Yes. I don't know what else was in the goodies directory, but GOG version includes editing tools (Build, Editart, Kextract, Kgroup), the _ZOO, _SE, and _ST example maps, and a bunch of documentation (Sector Effectors, Sector Tags, Sprites, .ART file format, Build).

That's great, then!
Thank you for answering.

There is no problem in that since what I want is just the "SDK" =) so I can change the art and make maps like in the "old days"..