Stave'n'Tabs - iOS and macOS notation and tablature editor with MIDI and MusicXML files support and chromatic...
NtEd - Music Score Notation editor.
Chordsheet Maker - Create chord sheets or lead sheets quick and easily from your iPad. Add rhythms, endings, segno, codas and all what's necessary for your musicians to know what's your music about. Transcription made easy!
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
Tonelib JAM - Create, edit, print and listen to tablature and guitar sheet music
music21 - Music21 is a Python-based toolkit for computer-aided musicology.