.GMK File

File extension gmk is related to the GameMaker, a platform for development of simple computer games available for Microsoft Windows.

A .gmk file contains project with source codes, settings, game data, audio data, graphics, etc. created and saved in the GameMaker program.

Files with gmk suffix can be most often found as game projects prepared using GameMaker video gaming development tool for Windows.

How to open:

Use GameMaker to open and work with .gmk files.

How to convert:

It is likely that some sort of export is possible using GameMaker. Usually to finished game.