I didn’t mean to get into a debate about what Open Source means (I pasted a link to the definition of the Open Source Initiative The Open Source Definition – Open Source Initiative), but was just trying to reframe the discussion to give it a more positive and constructive spin to foster collaboration from Autoware with as many simulator teams as we can.
By the way, from the link you pasted:
Despite the philosophical differences between the free-software movement and the open-source-software movement, the official definitions of free software by the FSF and of open-source software by the OSI basically refer to the same software licences, with a few minor exceptions
The Open Source Definition was copied verbatim from the Debian Free Software Guidelines, the only difference between Free Software and Open Source, is that the former is politically and philosophically motivated, whereas the latter is more about pragmatism.
As for the Unreal license, it seems fairly clear (at least to me) that only when you’re selling your game or application (i.e. you’re getting revenue from selling licenses) the royalties clause applies.
But in any case, neither you or I are lawyers, so let’s better leave it to the experts and focus on how Autoware can collaborate with the many simulation teams out there.