Nightingale is a completely free, open source audio player and web browser based on the Songbird media player source code. As such, Nightingale's engine is based on the Mozilla XULRunner with libraries such as the GStreamer media framework and libtag providing media tagging and playback support, amongst others. Since official support for Linux was dropped by Songbird in April, 2010, Linux using members of the Songbird community diverged and created the project. Contrary to Songbird, whose skins/feathers are copyrighted, Nightingale is licensed under the GPLv2, with portions under the MPL and BSD licenses.