mame/docs/license.txt

Unless otherwise explicitly stated, all code in MAME is released under the
following license:

Copyright Nicola Salmoria and the MAME team
All rights reserved.

Redistribution and use of this code or any derivative works are permitted
provided that the following conditions are met:

* Redistributions may not be sold, nor may they be used in a commercial
product or activity.

* Redistributions that are modified from the original source must include the
complete source code, including the source code for all components used by a
binary built from the modified sources. However, as a special exception, the
source code distributed need not include anything that is normally distributed
(in either source or binary form) with the major components (compiler, kernel,
and so on) of the operating system on which the executable runs, unless that
component itself accompanies the executable.

* Redistributions must reproduce the above copyright notice, this list of
conditions and the following disclaimer in the documentation and/or other
materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.