You can now download the complete MIDI 1.0 specification from the MMA as a PDF! This document was not available to the public until 2016.
Download the MIDI 1.0 Specification - look near the bottom of this page.
- midi.org - start here for all things MIDI!
- midi.org/specifications - for General MIDI, DLS, reference guides, etc
- MMA - MIDI Manufacturers Association
- MIDI Farm - backing tracks
- MidiShare - Grame - cross platform MIDI API
- Timidity - MIDI to WAV
Historically interesting links:
- HMSL - Hierarchical Music Specification Language, Forth based for Macintosh
- JavaMidi - MidiPort by Robert Marsanyi, Tom Erbe