@Suiseiseki
> Unfortunately, even during the time when copyrights or patents didn't apply to software, many businesses refused to publish the source code, claiming such was their "trade secret"
I don't think trade secret laws covered software before that point, either, and businesses who would have otherwise delivered the source code with their products suddenly found it in their interest to stop (ex. when Xerox refused to give the AI Lab the driver code for their new printer).
I think "trade secret" laws are of the relevant few laws (along with patents) that ought to be entirely abolished rather than reformed. If a business has what they consider to be their "trade secret" leaked out, then it's their fault and they should have no legal recourse to compensate for their mistake. I think this would eventually drive home the idea that keeping secrets from valuable clients is ultimately futile and hinders successful business.

> Currently, freedom-defending licenses take a crucial role in defending the freedom of the software.
I agree.

> I believe the quake source code was only released like 10-20 years after the main release, but that's a lot better than most.
The source to the original Quake was released under GPLv2 in 1999, 3 years after the game came out. IIRC it was one of the first commercial games to be ported to GNU/Linux. They seemed to follow a policy of releasing their code a few years after they were done with it, as they did for the engines for Quake 2, 3, and Doom 3/Quake 4, but they haven't followed up on this for a long time, unfortunately. I think it's a good example for game developers to follow, though it is preferable to just make the engines free in the first place (which some nowadays do).