.GMD

.GMD file extension

This is the basic program to work with .GMD extension

GameMaker: Studio

GameMaker: Studio Game 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

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.