Originally Posted by HCE
Except that in the mobile space, the overwhelming majority of applications do not make low level API calls. They all call higher-level API calls which are different for each distro. So essentially this is more like three different OSes, each of which just happens to be based on Linux. It isn't like the desktop space where applications will run on pretty much any distro. Each of these variants will have its unique ecosystem which won't overlap with the other. If the companies behind them play their cards right they could succeed in becoming a significant presence in the mobile space.
How does that fragmentation help Linux? It's not like it is easy to develop for more than one Linux distro anyway. Software vendors target RHES, SLES and Ubuntu LTS and let the rest of the users figure out installs themselves.
Your statement implies that somehow BSD, as the result of some legacy Unix code, is Unix and Linux isn't.
Yes. BSDs can trace back directly to the unix codebase. As can most uncertified unixes. Linux was a clean code base built against Unix APIs.
I frankly don't see why - the two systems diverged over 15 years ago and have changed significantly since. Not to mention the fact, that ever since 1992 when the lawsuit was settled, every other Unix-like OS (Linux included) has been free to incorporate BSD code while BSD itself cannot appropriate code covered by more restrictive licenses (which effectively means that it cannot appropriate any other "Unix" code at all).
That GPL is a one-way street is well understood by BSD users. On the plus side, BSDs have zfs and linux doesn't.
Also, in one sense, OS X is the least-Unixy of the lot because it is architecturally quite different from all the other Unixes. It comes from NextStep which was based on the Mach microkernel, which has nothing to do with the original AT&T source code. Everything else has a monolithic kernel like the original Bell Labs version did.
The userland is from FreeBSD and NeXTStep which also inherited BSD code. OSF/1 was also mach based and a true unix. These are all "genetic" unix systems that can trace to code from original unix systems (SysV or BSD).
Well, it isn't, as you say, that easy - it is going to require a non-trivial amount of time and effort, not to mention money - but, in the larger scheme of things, it is not terribly hard. I have seen news reports that say that Red Hat and Novell are, regardless, in favor of the idea but the final arbiter of all kernel changes is Linus and he is adamantly against it.
It isn't as if there hasn't been kernel changes to make RHEL EAL 4+. That they don't get into the official kernel is just something that RH has to deal with when patching.