.IMF File Extension
What is an IMF file?
Id Music File (IMF) created for use in id Software video games; contains data similar to MIDI files in that the files do not contain sampled digital audio, but rather contain musical notes; used to send music data for playback on AdLib sound cards.
The IMF file format was created by id Software for their video games. Due to low-quality nature of the sound and the proprietary format (AdLib sound cards only), the IMF format is no longer used.
Some programs, such as AdPlug, emulate AdLib sound cards and can play IMF files.