Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
Captain Chords - Write chord progressions in your favorite DAW
NtEd - Music Score Notation editor.
RapidComposer - MusicDevelopments RapidComposer: Music Prototyping and Automated Composition Software
ScoreCloud - ScoreCloud, free software that instantly turns your songs into sheet music. As simple as that!
Cthulhu - VST MIDI-FX plugin for harmonic inspiration