SYS V needs to go open next, not that overloaded slowlaris, but lean mean SYS V
I was under the impression that the entire POINT of SYS V was for the major UNIX vendors to re-implement the guts of Unix as a clearly, enforceably, proprietary product (after the CONTU recommendations and the resulting copyright law changes explicitly extended copyright to software), then move to it and orphan the original development thread. (This might make opening it a hard sell to the members of the consortium.)
There were at least a couple issues with the proprietary status of the AT&T code:
One issue was that AT&T was still a government-regulated utility monopoly and there were some requirements about disclosing and releasing non-telephone-related inventions they came up with.
The big issue was that, before copyright applied and before software patents were hacked up (by recasting software as one embodiment of, or a component of, a patentable machine or process), the only protection was trade secret and the related contract law. Trade secrets generally stop being enforceable when the secret out of the bag (with some details about whether the claimant contributed to the leak). Bell Labs had shipped code to a LOT of educational institutions. When the U of New South Wales used the System 6 kernel code and an explanation of it as the two-volume text for an Operating System class, the textbooks became an underground classic. This, along with AT&T's benign-neglect licensing policies, led to the burst of little, cheap, generic UNIX boxes, as this was also when microcomputer chips were just becoming powerful enough to do the job.
Up to then a big barrier to entry was that every new machine needed a custom O.S. to deploy, and these were enormous, machine specific, and mostly in assembler. That made it an expensive, undertaking, suitable only for financial giants. But all but under 2,000 lines of Unix was in C, and the entire kernel, which included essentially all the platform-specific code as a subset, was well under 10,000 lines of code. If you had a C compiler and assembler for your new machine, it was a matter of a few man-months to port it and get it up and running. Essentially ALL the utilities and applications came right over. You didn't have to train users, either, because they all worked pretty much just like what they'd used in college.
The game was:
1. Grab a bootleg copy of the code.
2. Port it to your machine and get it working.
3. Go to AT&T and ask for a license "to port Unix to our new machine and sell it."
4. AT&T, as a matter of policy, completely ignores any "violations" you may have committed during the porting phase and cuts you a license at a very reasonable price.
5. You "port Unix in an AMAZINGLY short time" (like the ten minutes it takes to tell Sales to go to market) and you're in business.
6. You (with your new business) and AT&T (with their small cut) slap each other on the back and laugh all the way to the bank. PROFIT! for you. (profit) for AT&T.
7. Because of the policy in 4., everybody ELSE manearly everbody's king a new machine knows they can do the same thing. So many do. AT&T gets a rakeoff from ALL of them. PROFIT! for AT&T. Far more than if they went dog-in-the-manger, held up the first few for all the traffic would bear, and got no more customers for Unix.
And because of this, it was in nearly everbody's interest to NOT challenge the AT&T-proprietary status of Unix. And it stayed this way until SCO's management screwed up and altered step 4. (Even then the case turned on other issues, so it never did come to the point of attacking AT&T's claim that Unix code was proprietary.)