DeePsea is a Doom level editor and WAD resource manager with support for ZDoom editing via custom configuration files. A GL port called R3Dedit is used for 3D texture editing, 3D sector editing as well as moving any sprite around in 3D mode. It was developed by Sbsoftware and is a shareware application. There is no time limit, but the maximum size of levels a user can create is limited to 800 linedefs for the unregistered version. DeePsea's development is ongoing.
Trivia: almost every feature within the program can be accessed by pressing the F7 key.