There are 2 file types use the .MTX file extension:
1. MadTracker 2 Extension
Adds extra features or additional format support to the MadTracker audio tracker.
Updated: June 7, 2006
2. MetaStream Scene File
Three-dimensional scene saved in the MetaStream ASCII text format; uses XML-style tags to store information about the scene, such as global scene options, object (instance) hierarchies, camera locations, and animation data.
Updated: July 4, 2008