http://lilypond.org/web/
 GNU lilypond = OpenSource ¾Çº¸ Á¶ÆÇ ¾ð¾î/ÇÁ·Î±×·¥.

 * text input -> command line compilation -> ps/pdf output
 * Cross-Platform
 * TeX-friendly, but not a sort of TeX-macro. having nothing to do with MusiXTeX.
 * simple syntax, wonderful sheet.