I don't claim to be a legal expert, but I am a subscriber to Moshix's YouTube channel, where only a year or two ago Moshix and a number of other hobbyists were formally engaged with IBM, attempting to persuade them to release to our community the distribution and source for MVS/XA, a vintage 1983 release.
IBM turned them down flat.
So I myself would definitely assume nothing regarding IBM's allowing a vintage 2011 release of Z/OS somehow finding its way to a well-known public domain site.?
Put another way, if it WERE legal, we would certainly be hearing about it, most of all from IBM themselves, as it would be to IBM's great PR advantage to publicize such a massive release of proprietary intellectual property to the public domain.? Does such a press release exist?? Not that I've been able to Google...
As I don't want the legal department of Big Blue knocking on my door anytime soon, I'll be sticking to MVS 3.8j and the other known public domain OSs until I hear differently from IBM.
