There is only one file type that uses the .XPF extension:
LMMS Preset File
Preset file created by LMMS (Linux MultiMedia Studio), a music production program; contains instrument settings presets; includes instrument settings data like the project version, instrument track settings, instrument names, and effects.
To create the XPF file, click the save icon in the "Default preset" window, name the file, choose your save location, and click.
You cannot open the XPF file by clicking on it, you must put it into the "presets" folder in your user directory. Then open the LMMS application, select the "My presets" star icon on the left side, navigate to your XPF file, and double-click it.
Updated: September 8, 2013