Some thoughts on licencing.
Most emulator projects use the #GPL license because their projects are community driven.
You can tell when a project has a company focus in mind by looking at the license.
When a project is a GPL one, what the project wants to do is to protect the members work by forcing companies to return the code.
@blabber Consumers do not benefit from having the source code closed. They cannot learn, improve or redistribute proprietary software, therefore the only freedom that BSD and MIT provide is the freedom of closing the user's freedom.
Companies do benefit from closing the source code, but users don't.
They explained that they wouldn't do that because other companies had already abused the work of the community without giving back a thing. So in order to protect people's work, copyleft was a requirement.
For people who care about, support, or build Free, Libre, and Open Source Software (FLOSS).