.GMD

.GMD file extension

This is the basic program to work with .GMD extension

GameMaker: Studio

GameMaker: Studio Game Maker File

GameMaker Studio lets you start creating your game from scratch. It has two options: Drag-and-Drop, and Game Maker Language. The first one is by far the easiest, since you only need to select the elements you want to include in your game, and drop them into the workspace. The second one needs you to have a solid programming knowledge... (more)

The program works with the following extensions: gmd, gm6 and gmk

.GMD extension is also supported by the following programs:

Winamp

Winamp Winamp media file

Winamp player is designed to cover the large area of media file types.
jetAudio

jetAudio Winamp media file

JetAudio Basic is a video and music player but it also can burn CD's,record,etc.