Commodore Amiga MIDI Driver (CAMD) is a shared library for AmigaOS which provides a general device driver for MIDI data, so that applications can share MIDI data with each other in real-time, and interface to MIDI hardware in a device-independent way.
AmigaOS itself did not support MIDI until release 3.1 when Roger Dannenberg's CAMD library was adapted as the standard MIDI API. Commodore's version of CAMD also included a built-in driver for the Amiga serial port. The Poseidon USB stack contains the camdusbmidi.class.
References
Commodore Amiga MIDI Driver Wikipedia(Text) CC BY-SA