midiO 1.3 for Mac can be downloaded from our website for free. MidiO.zip is the most frequent filename for this application's installer. The application lies within Audio & Video Tools, more precisely Streaming Media. The most popular version among midiO for Mac users is 1.3. This free software for Mac OS X was originally designed by RetroWare.
From the developer:
Audio Unit plugin for DAWs such as GarageBand that don't support MIDI output. This plugin allows one to drive a MIDI based synthesizer from any DAW that supports software instrument Audio Units.
You may want to check out more software for Mac, such as Five Live, HBR1 Dream Factory or SolidGold14k Radio, which might be similar to midiO.