Lazy Doomers' Patching Tool

The Lazy Doomers' Patching Tool, also called ladopato or doompatcher, is an IWAD patching utility to identify IWAD versions and upgrade or downgrade them to any other supported version.

Supported IWADs include the registered DOOM.WAD, DOOM2.WAD, TNT.WAD and PLUTONIA.WAD. The rarer Anthology versions of the Final Doom IWADs are not supported, however.

The tool's homepage warns that the tool is outdated and should not be used.