This is the Doom Patcher as an EXE for ease of use for Windows users. No need to install Python!
You can specify the Doom executable to load on the command line or you can drag-and-drop your Doom executable onto the Patcher.
The Doom Patcher will work with the Doom executable that's 709905 bytes. This is the executable that came with Doom v1.9 and Doom 2 v1.9 (The Ultimate Doom and Final Doom are not supported).
Documentation: here