MIDI Manufacturers Association Incorporated (MMA)
Formed to maintain the MIDI specification as an open standard. The site contains the MIDI specifications, information about the MMA and news related to MIDI and the MMA. Part of the website is members only.

MIDI Technical Fanatic's Brainwashing Center
Contains MIDI tutorials, programming information, technical documents, free software, and well-arranged MIDI files.

The MIDI Farm
A starting place for up-to-date information on current MIDI based music composition products.

The MIDI Specification
A free version of the MIDI Specification.

The MSQ Project
Description of the MSQ file format and MSQ tools, which include MSQ to MIDI and MIDI to MSQ converters.