LilyPond

LilyPond is an open-source program to produce sheet music, using a text-based input format to supply music to be printed.

Mediawiki's Score extension allows the embedding of music, input using LilyPond notation, in wikis.

The first line of a file should be a version statement like this:
 * \version "2.16.2"

The version number will vary by which LilyPond version the file is intended for.

Links

 * Official site with downloads and manuals
 * Notation reference
 * Text input tutorial
 * Input file format
 * Usage of LilyPond notation in Mediawiki