These files are meant for recovering unmaintained, no-longer-commercial software or your own software.

Download all files](/static/gamemaker/gamemaker_decompilers.zip)

Game Maker Decompiler (8.0-8.1): Decompiler.exe

Run using

Decompiler.exe GAME.exe

Game Maker Decompiler (version 7 and older): gmdecompiler_v2_1.zip

GUI program needs Java.

Uncompiler: Uncompiler.exe

Run using

Uncompiler.exe GAME.exe

Source

biancagames.com/tools.htm