DoomCenter E1 Mapping Contest (E1CONTEST.WAD)

Doom Center was an important fixture of the community during the post-source port boom. It was something of a media hub in its promotion of PWADs and their authors. It eventually deactivated with the death of its host but some of its staff went on to join Doomworld. Snapshots of the site were thankfully preserved via archive.org but most of its content and enthusiasm have not figured into its legacy. I only know of Doom Center's existence because it hosted a map-making contest during a week that celebrated the shareware episode in 2001. John Romero himself judged the submissions; the winner received an autographed copy of the Ultimate Doom.

Nex Credo (NEXCREDO.WAD)

Lots of Doom authors set out to craft a megaWAD. Many never make it to replacing all 32 levels and the half-finished works oftentimes languish in obscurity, something to be worked on a rainy day. The author occasionally sees fit to put the finishing touches on it and shove it out the door, grateful to be clean of it. The audience may despair of the squandered potential (as was the case with Vanguard) but they at least have something to play. Released in 2016, Jay Trent's Nex Credo follows in that grand tradition. It's an 11-level episode for Doom II and he apparently intended to pattern the final product after its starbase / city / Hell themes, just sketched by Jay's hand.

900 Deep in the Dead (900DEEP.WAD)

900 Deep in the Dead is a takeoff from the popular 100 Lines project, the latter began by Adam Windsor. The concept - make a map with only 100 lines. The challenge is in creating something that both looks okay and is also entertaining. Doomworld Forum superstar Jay "Jayextee" Trent took the idea and ran with it for a full episode replacement for Doom's Knee Deep in the Dead. Trent tackles the constraints in what I'm assuming are staples of working within 100 lines, using abstract geometry, double-sided linedefs separated by height to reuse walls, and other bits of level geometry for monster closets.