idf extension is associated with MIDI Instrument Definition File. You have chance to open idf files with IDF Editor.
The settings which used with Midi keyboard(org) and similar devices are saved in idf files. In this file, there are informations about device ID number, part names, keyboard and channel numbers. Idf files are generally produced by softwares which create MIDI. And these file formats can`t be opened directly on computers. To get detailed information, please check the following links.
What to use idf
which page related to idf file
idf Related Searches
You can check related links about idf fileextension.