MuseScore is a free cross platform WYSIWYG music notation program, licenced under GNU GPL. Some highlights include (a) WYSIWYG, notes are entered on a "virtual note sheet," (b) Unlimited number of staves, (c) Up to four voices per staff, (d) Easy and fas

LilyPond is an automated engraving system. It formats music beautifully and automatically, and has a friendly syntax for its input files. It is Free Software (‘open source’).

Open Digital ScoresOpen Score Format is an open and non-proprietary distribution, interchange and archive file format for digital scores (sheet music). The motivation for developing the format is to improve choice - both for content creators and consumer