From the Buzztard Team:

The buzztard team has released version 0.5.0 “crown of thorns” of its buzz-alike music composer. All modules got extensive improvements over the last release from almost a year ago. Give it a try, join hacking and report bugs.

• Split the api into library and instance api. Lots of code and build cleanups.

• Several bug fixes and better compatibility.

• Rewrite of internal pipeline management. One can now play partially connected songs, and add/remove plugins while playing. Buzztard can play notes while editing. More robust saving of songs. Lots of bugfixes and UI improvements.Better user-guide including three small tutorials. Initial support for python and javascript via gobject introspection.

• Lots of improvements in the buzzmachine wrapper. Buzz index support for categories. Make machines live-playable. More resource efficient.

project-page: http://www.buzztard.org
screenshots: http://www.buzztard.org/index.php/Screenshots
downloads : http://sourceforge.net/project/showfiles.php?group_id=55124