http://mamedev.org/?p=422
MAME is now Free and Open Source Software
04 Mar 2016
After 19 years, MAME is now available under an OSI-compliant and FSF-approved
license! Many thanks to all of the contributors who helped this to go as
smoothly as possible!
We 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. We had limited choice to 3 that people
already had dual-license MAME code with.
As a result, a great majority of files (over 90% including core files) are
available under the 3-Clause BSD License but 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.
If you have contributed to the MAME source code and believe we have not
contacted you, please reach out to us at our contact page.
Please note that MAME is a registered trademark of Nicola Salmoria, and
permission is required to use the "MAME" name, logo or wordmark.
http://www.cnbeta.com/articles/480843.htm
街機模擬器MAME已變身自由軟件
流行街機模擬器項目MAME（代表 Multiple Arcade Machine Emulator）修改了許可證，
正式成為自由軟體。MAME以前採用的是一個修改版的BSD許可證，禁止商業性質的發行，
因此不符合自由軟體定義。自由軟件許可證允許你在保證軟體自由的條件下自由的發行，
其中包括商業性的出售。
MAME項目聯絡了所有的代碼作者，修改了許可證，它的絕大部分文件採用的是
3-Clause BSD License授權，而整個項目是採用GPL-2.0+許可證授權。
重點來了....
http://mamedev.org/?p=423
Attention for all derivative builds
04 Mar 2016
Please be aware that only files distributed by Mamedev (those available via
the official GitHub) have been subject to the relicensing efforts.
If you maintain a derivative build please be aware that you will have to gain
the correct permission from all contributors for any extra code you have in
your build. Code that was distributed under the previous MAME license can not
be included or linked to MAME from this point forward without being
relicensed, requiring permission from all contributors to that code.
This applies to all derivative builds, including MAMEUI, MESSUI etc. so if
you have a derivative build based upon that code you will need to either
rewrite from scratch or obtain permission from all contributors to the code
in order to relicense.
各分支版本注意（只要你不是 MAME 本家的）
各程式碼授權僅提供 MAME 使用，非 MAME 的話請自行重寫程式，或者跟各
程式碼作者洽詢授權。
（影響包含 MAMEUI / MESSUI 等這類將 FrontEnd 整合版）
目前影響範圍： MAMEUI MAMEUIFX 不幹了，MAME PLUS! 前兩版就 Bye 了....
沒有影響的就純 FrontEnd，如 MAME Plus 的 GUI 程式、MAMEUI 作者的 IV/Play 等
後續狀況就怎樣發展了.....