MAMEWorld Forums - EmuChat - Re: Mame used Commercially

> I’ve read that Mame can be used commercially and that it cannot. Which is correct
> please? Can you buy a licensed version etc to use it commercially?

Historically, MAME's license prohibited commercial use across the board, regardless of context.

Over the years, it became increasingly obvious that the commercial-usage prohibition was preventing legitimate use of MAME in certain contexts that can be considered "commercial" if you squint a bit: Things like being used in a museum, where the museum happens to charge a token amount for tickets. Meanwhile, it did absolutely nothing to prevent shady companies from simply using MAME in commercial products regardless.

With that in mind, over the course of 2014 to 2015, the MAME team engaged in a massive push to change the license of the project.

Since every piece of code that had been written over the prior 17-18 years was submitted under the original license, with the "no commercial use" clause, the team had to reach out to every single one of hundreds of prior contributors in order to get their consent to move over to a more FOSS-recognized license.

For the most part, the relicensing project was a wild success: Other than the authors of around 3 drivers out of hundreds, everyone was able to be contacted.

With that in mind, the majority of MAME's core is licensed under the BSD 3-clause license, which permits free usage even in closed-source applications, as long as attribution is given somewhere. Driver authors themselves can also use GPLv2, as it does not have the "viral" nature of GPLv3, or any other license they choose, although any source code contributions must be done under a license that is at least as permissive as GPLv2 or BSD-3-clause.

This is part of why the push to re-write the Yamaha FM audio cores recently was such a big deal: Although a significant fraction of the core devices were BSD-3-clause, which not only permits commercial usage, but doesn't require release of the product's source code on request - making it more attractive for use in commercial products - an immense number of systems used Yamaha FM chips for audio, meaning that overall, most systems that the greater public cares about would still have been encumbered by GPLv2. As the new FM cores are licensed under BSD-3-clause, this widens the scope of potential commercial usage considerably.

Nonetheless, the concept of "commercial usage" of any given piece of software is something that the average person shouldn't go into without the advice of an attorney who is actually familiar with IP law. That applies to nearly everything, not just MAME.

> I’ve also read that roms cannot be used commercially unless you have the original
> arcade boards or have express permission from the copyright owners. Does anyone know
> if it’s true regarding if you own the boards you can emulate commercially?

It depends on the country and jurisdiction in which you reside. For the most part, copyright law in the US does not protect format-shifting for commercial software. Just because you own the board set for a given game doesn't necessarily mean that the contents of the ROM chips on that board are byte-identical to any particular ROM set in MAME, and so your best bet would be to dump the ROM chips from each board you have, and use those with MAME. Owning a board isn't a free license to just go and download ROM chips that some other person has put up for download.

Again, for the most part, this is something you should be consulting an attorney about if you're really serious about it, not asking a flock of idiots like us on the Internet.