.GMD

.GMD file extension

This is the basic program to work with .GMD extension

GameMaker: Studio

GameMaker: StudioGame Maker File

You can make games with backgrounds, animated graphics, music and sound effects. You can do anything you want with the games you produce. GameMaker comes preloaded with a collection of freeware images and sounds to get you started. GameMaker allows you to make exciting computer games, without the need to write a single line of code... (more)

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

.GMD extension is also supported by the following programs:

Winamp

WinampWinamp media file

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

jetAudioWinamp media file

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