Tools Used by John Romero During DOOM Development
1. DMapEdit and BSP
The very first internal map editor for DOOM was DMapEdit, written by John Romero himself in 1993.
It was a prototype tool used early in development before the full internal editor existed.
This tool allowed him to place sectors, walls, and entities in the game’s early test levels.
The team then used a program called BSP (Binary Space Partitioner) created by John Carmack to compile the geometry.
This was a crucial step because it organized how the 3D space would be rendered efficiently on DOS hardware.
In Romero’s words:
“We were designing rooms that the engine couldn’t even draw yet. Carmack was coding the renderer as I was building the test maps.”
2. DoomEd (Internal Map Editor)
The main level editor used by id Software was DoomEd, built by John Romero in NeXTSTEP, the same operating system used on John Carmack’s NeXT computer.
DoomEd was never released publicly.
It allowed level designers like Romero, Tom Hall, and later Sandy Petersen to:
Create rooms, doors, and trigger sectors.
Assign textures and lighting values.
Place monsters, items, and spawn points.
It was a text-driven, highly technical tool — powerful but not user-friendly.
Romero used it to design iconic levels like E1M1: Hangar and E1M7: Computer Station.
3. NeXTSTEP Environment
Both Romero and Carmack did most of their DOOM work on NeXT computers, which ran a Unix-based operating system called NeXTSTEP.
It provided powerful multitasking, coding tools, and a clean interface that was far ahead of standard DOS machines.
The engine was coded and compiled on NeXTSTEP, then tested on DOS PCs.
Romero once said:
“Carmack’s NeXT box was like a magic machine. I’d build maps, he’d code new features, and we’d test them right away.”
4. Texture and Asset Tools
Art and texture creation were handled by Adrian Carmack and Kevin Cloud using programs like Deluxe Paint II and NeXTSTEP image converters.
Sprites and wall textures were hand-drawn, then imported into the DOOM data structure as WAD files.
5. Playtesting and Debugging
For gameplay testing, Romero and the team used internal debug commands such as IDCLIP, IDDQD, and IDKFA — cheats that were originally added for development and testing, long before they became iconic among players.
They played multiplayer tests across their office network to balance levels and monster placement.
DoomEd – Created by John Romero. Used for level creation on NeXTSTEP.
DMapEdit – Early prototype editor by John Romero for testing geometry.
BSP – Program by John Carmack that compiled map geometry for fast rendering.
NeXTSTEP – Operating system by NeXT Computers used for development and compiling.
Deluxe Paint II – Tool by Electronic Arts used for sprite and texture editing.
Internal WAD tools – Custom id Software utilities for packing maps, sprites, and sounds into WAD files.
Legacy
While fans used tools like DEU later, the id Software team relied entirely on their in-house pipeline.
After DOOM’s release, the format of its WAD files inspired modders to reverse-engineer the tools, giving birth to the editing community.
Romero’s DoomEd was never released publicly, but its structure influenced nearly every DOOM editor that came after it — including DEU and SLADE.
Romero built the levels that defined DOOM using tools that only existed inside id’s walls.