19 years after its initial release, the Multiple Arcade Machine Emulator (MAME) has completed its transition to a free and Open Source model.
The development team behind it have spent the last 10 months trying to contact all people that contributed to MAME as developers and external contributors and get information about desired license. As a result, over 90% (including core files) of files are now available under the 3-Clause BSD License, but the project as a whole is distributed under the terms of the GNU General Public License, version 2 or later (GPL-2.0+), since it contains code made available under multiple GPL-compatible licenses.