There is only one file type that uses the .MTXT extension:
MOPEKS Text File
Text file created by MOPEKS, a program that generates multiple programs run by its script to use each other to solve problems; contains trial problem data; when it's clicked, the application references the data to run a trial to solve the problem;
When you open the MOPEKS application for the first time, a window will open asking if you want to make the MTXT file associated with the MOPEKS program, click.
MTXT files are located in one of the class folders found in C:\MOPEKS\Library\Problems User.
NOTE: Other MOPEKS associated files include .MPKT, .MSCT, and .MTHD.
Updated: July 6, 2013