That's easy,some BigCo would've co-opted it, paid developers to go the last mile and polish it to make it usable, and make it incompatible with everything out there and sold it. Perhaps Sun or IBM or even Oracle. E.g See OS X and to a lesser extent, Linspire/Lindows.
Hasn't happened to PostgreSQL and I doubt it would have happened to Linux. The leader and community are pretty strong with Linux and that is not about the GPL. I would imagine some folks would fork it, but that always is a losing game from a business point of view (paying for a fork vs. patching and getting everyone to pay). Having BSD licensed kernel at that point in history during the AT&T BSD lawsuit would have been seriously interesting.
Maintaining a fork isn't a big issue if you have enough resources, considering that if Linux was BSD licensed they would still have had their proprietary fork mirror it "close enough" to pull in at least some of the big changes from the main Linux tree.
Android seems to work in this manor to a certain extent (although they open source patches back when they have to because of GPL).
You would most likely have ended up with a bleeding edge open source version and several more conservative closed ports.
Bear in mind that a lot of the reason Linux development is strong is because many of it's developers are paid to work on it and then contribute back (again because of GPL). If a company could gain a competitive advantage by paying the same people to work on a closed fork..
I think the problem with maintaining the fork is the speed of development of the community, and let's face it, it is much easier to monetize hardware than software in the open source world. The fear of being left behind and weird vendor specific errors should not be discounted.
I agree though, someone would try. I just think Linux would have done just as well with a BSD license being released at the time it was. The people and the timing deserve more credit than the license.
See also the http://en.wikipedia.org/wiki/Unix_wars, during which the industry mostly lost a decade of work entombed in proprietary forks. Tit-for-tat has better survival characteristics, and the GPL is no exception.
I strongly disagree with this phrase. I'm not saying making Linux usable is 90% of the work; it isn't, but it isn't "the last mile" either (maybe that + customer support + developer relations and evangelism equals to 15-20%).
I meant last mile as in developer scratching their itch. It's much more sexy to work on new and interesting things(that mostly break existing things) rather than the doing the grunt work on backwards compatibility, bugs or documentation, not to mention enforcing a central vision and design on developers(ever hear of OSS devs quitting or making forks because of differences in opinion?) .
