Jun 2, 2009 at 8:06 AM
Edited Jun 2, 2009 at 8:09 AM
I am not a lawyer. Licensing is fundamentally a legal question, not a technical question. And you cannot trust anything from a lawyer that you're not paying. So if you're betting a business on this (or any other library / software), get an attorney to look
at the license and give you an actual legal opinion.
Having said that, the intention is for the code & binaries to be usable in whatever way you like. Take just the binaries you want, and distribute them however you like. You can also distribute the source code, or even make changes to it and distribute
them. What you cannot do:
1) Claim that you wrote it.
2) Remove copyright notices on the current source files or binaries (which are in the binary's resources).
3) Sue anyone over patent infringement in the Unity software and continue to use it.
4) Edit the source code and release it under a different (well, incompatible) license. The upshot of this is you can't take the unity source and re-release it under GPL.
5) Your software's license must be compatible with Ms-PL as far as redistribution of Unity is concerned. Commercial licenses are fine.
I think that's about it. It's an OSI approved open source license, and is about as free as you can get.
Again, though, if you're actually concerned, get an attorney, don't listen to an engineer. The law doesn't make anywhere near enough sense for an engineer to understand. ;-)