About Tab - Information on Wayne Cripps' TAB format
Audio, MIDI & music on the Apple Mac - MacMusic
Avid - Sibelius Music notation
Desktop Music Handbook - Cakewalk info about midi
DjangoTab Lute tablature and noation editor and composer
Fronimo tablature editor (via newsgroup)
MarmaladeFoo: Typeset tablature in Excel
MuseScore | Free music composition and notation software
Music Notation Software FORTE - Music Writing & Composition
MusicXML - music exchange format
PDFtoMusic Pro - Play back and save music pdfs to XML and other formats
SpeedScore - Music engraving for Mac Classic OS