Haze wrote: to further clarify
this applies to the MAMEUI / MESSUI code itself, we have made no effort to relicense it. Anybody using it (including John IV etc.) will need to seek permission of all authors and have them agree on one of the compatible licenses before publishing another build.
it also applies to any additional code in other builds, for example, things like image filters, you'll need permission from each of the authors of those filters in order to relicense them and include them.
The same applies to any other non-trivial code changes.
Please be aware that from this point onwards the licensing requirements are very strict, every file you use should have a proper license text at the top stating the copyright holder(s) of that file and the license they've agreed to distribute it under.
As MAME now contains GPL code any changes made in future versions to files distributed with a GPL license cannot be backported to older versions / forks of older versions (eg mame4all etc.) as the previous MAME license(s) and GPL are NOT compatible.