Rationale - Sequencer for extended just intonation
Lilypond - Music engraving program
Xenpaper - Text-based microtonal sequencer
Ratioscore - Just intonation tool
Scale workshop - Design and play microtonal scales in your browser
Scala - Tool for experimentation with musical tunings
Alda - Text-based programming language for music composition
WereSoCool - A language for composing microtonal music
tune - Make xenharmonic music and create synthesizer tuning files for microtonal scales
New Musical Resources, Henry Cowell
Genesis of a Music, Harry Partch
Maximum Clarity and other writings on music, Ben Johnston
The Arithmetic of Listening, Kyle Gann