FreeMIDI is a complete MIDI operating system. It ships free of charge and is automatically installed with all Mark of the Unicorn music software products.

FreeMIDI automatically detects what type of MIDI interface is connected to the Macintosh serial or USB ports, automatically detects what MIDI devices are connected to interface (it "knows" over 200 types of devices), and provides a graphical representation of their MIDI studio.

FreeMIDI also provides pop-up sound lists for over 100 popular MIDI synthesizers-as well as generic support for any General MIDI device. It even includes advanced features such as inter-application communication, multiple application real-time synchronization, and support for Digidesign's Sample Cell Nubus card.