There is only one file type that uses the .MMPZ extension:
LMMS Project File
Project created by LMMS (Linux MultiMedia Studio), an application that enables you to create and mix audio; contains LMMS project data such as sound effects, instrument settings, tempo, pitch, added .XPF preset files, volume, and controllers; exported as .WAV and .OGG audio files.
To create the MMPZ file, click the save icon in the top-left of the application or select, name your project, choose the save location, and click .
To open the MMPZ file, you can simply double-click the file. You can also open the project inside of the application, select, navigate to your file, select it, and click .
NOTE: LMMS replaced the .MMP file extension with the MMPZ extension.
Updated: June 19, 2016