NtEd - Music Score Notation editor.

DaCapo Editor - DaCapo Editor is a free Open Source music sheet editor which allows to easily create nice looking partitions. It is available as a web application as well as a desktop application for Windows, MacOS and Linux.

Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.

music21 - Music21 is a Python-based toolkit for computer-aided musicology.

ABCexplorer - ABCexplorer is a musical creation utility that comes with advanced support to create, edit, play, convert and manage musical files with ABC text format support.

tonica fugata - Composing it for you... Automatic three and four-part composition (styles: J.S.