When you ask "why did big company X make strange choice Y regarding licensing or IP", 99 times out of 100 the answer is "lawyers". If the Plan 9 group had had its way, Plan 9 would have been released for free under a trivial MIT-like license (the one used for other pieces of code, like the one true awk) in 2003 instead of creating the Lucent Public License. Or in 2000 instead of creating the "Plan 9 License". Or in 1995 instead of as a $350 book+CD that came with a license for use by an entire "organization". Or in 1992 instead of being a limited academic release.
Thankfully I am not at Lucent anymore and am not privy to the tortured negotiations that ended up at the obviously inelegant compromise of "The University of California, Berkeley, has been authorised by Alcatel-Lucent to release all Plan 9 software previously governed by the Lucent Public License, Version 1.02 under the GNU General Public License, Version 2." But the odds are overwhelming that the one-word answer is "lawyers".
I agree the 2000 and 2003 releases' strange custom license terms sound lawyer-driven, but weren't the 1992 and 1995 releases' terms also driven by hopes of commercial exploitation? My impression was that during this period AT&T still hoped they'd be able to license Plan9 for $$$ to a vendor, like they had done with Unix, which meant they wouldn't want to release the code under a permissive license.
Yes, but who tells you "you can't do that because we want to keep open the possibility of making money later"? The lawyers.
AT&T gave away Unix during Unix's formative years, because AT&T's government-granted monopoly disallowed it from making money on computers. They didn't make any money on Unix then. They tried later, and made some, but what a sense of loss about what might have been if only they'd been charging from the beginning! Of course, if they'd been charging from the beginning, it's hard to say Unix would have been so popular.
If you don't want to see a proprietary fork of your code, you should use GPL. If you don't mind seeing proprietary forks of your code, you can use BSD, Apache, MIT or any other more "permissive" license.
I don't think Plan9 has much commercial value in it left, but they may consider it would be awkward if, say, EMC or Cisco incorporated some of its technologies (Plan 9 had some interesting ideas about storage and network transparency) into their proprietary products without paying for them. It's easy to sympathize with the small garage inventor and to think it's nice for you to subsidize small innovators, but it's much harder to do the same with corporations that would patent-extort you the moment they realized they could gain some advantage from it.
Apple gives people who want to make use of their beautiful code the finger. Why not do the same to potential Steve Jobs'? If BSD had been licensed under the GNU GPL, OS X would either have to have been built from scratch, or be free software.
So? That doesn't change that Apple usage of FreeBSD codebase is still a net win for the FreeBSD project. It is still a win-win situation even if the win isn't totally symmetrical.
Finally someone that actually understood what I meant. Gaining traction is a lot more important for getting work done than the contributions back from *GPL ever has been.
This argument is consistently colluded with the other argument for open and transparent software. They are two topics independent of each other, IMHO. If you care about open software, it does not imply you care about preventing others from using your software in a leechy fashion.
So you acknowledge today some people do already leech as you put it, under the GPL. It may be a violation, and the other party may laugh as they are in a different juridiction.
So, what was your point again?
We have a law against theft, yet there are continous occurences of people stealing and getting away with it, so by your logic we should remove the law against theft.
If you look at the note on the home page[1], they needed to get permission from Alcatel-Lucent for the license change. They may not have been able to sell them on BSD.
This isn't a shame, it does nothing. Plan 9 was already released under a BSD style license (one with an absurd amount of pointless legalese, but non-copyleft nonetheless). This is simply releasing it with additional restrictions so that people who are contributing to GPL software can use it now too.
Thankfully I am not at Lucent anymore and am not privy to the tortured negotiations that ended up at the obviously inelegant compromise of "The University of California, Berkeley, has been authorised by Alcatel-Lucent to release all Plan 9 software previously governed by the Lucent Public License, Version 1.02 under the GNU General Public License, Version 2." But the odds are overwhelming that the one-word answer is "lawyers".