Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
NtEd - Music Score Notation editor.
Guitar Pro 7 - Create, play and share your tabs
Synfire - The comprehensive Music Prototyping Studio for professionals and enthusiasts.
MMA - “MMA—Musical MIDI Accompaniment” is an accompaniment generator.
Sundog Scale Studio - The MIDI chords and melodies laboratory