OSNews

But, here's the point: OS X rests on an open source core. It's development began several years after Linux and the BSD's first appeared on the scene.

Which is just not true. OS X is a direct continuation of the NeXT codebase, which was started in 1986. That codebase itself was based on Mach (a derivative of BSD), and on BSD 4.x, the latter of which saw its first release in 1980. After Apple bought it in 1997, they updated large parts of the system with code from FreeBSD, NetBSD, and CMU Mach. The only truely new components in OS X 10.0 were Aqua, Quartz, OpenGL (though, the bulk of the actual OpenGL implementation is NVIDIA's and ATI's code!), CoreAudio, the IOKit, and user-space apps like the Finder and Configuration tool. The rest of the OS was "NextStep 5.0".

In short, OS X is a codebase that has been through 25 years of development at major universities like Berkeley and CMU, and 20 years of development at NeXT and then Apple. Nearly that whole time, it has had at least dozens and more often hundreds of people working on it. In comparison, Linux is *very* recent.

Let's do a timeline trace to give you an idea of how old the two codebases are, relatively.

1977: First release of BSD. Linus is 8 at this point.
1979: BSD ported to VAX. It has over a thousand users at this point. Linus is 10.
1980: DARPA starts funding BSD. Linus is 11.
1982: Apple becomes first personal computer company to reach $1 billion in sales. Linus is well on his way to completing middle school.
1984: Apple releases the Mac. Linus is still a high-school underclassman.
1985: Jobs leaves Apple ands starts NeXT.
1985: GNU project is started to recreate UNIX in its own image.
1985: CMU starts the Mach project.
1986: 4.3BSD is released, with the BSD TCP/IP stack. This BSD throughly resembles modern versions. Linus applies for college.
1987: Apple publishes its first Human Interface Guidelines. These guidelines are the product of intense human interface work at Apple over the better part of the 1980's.
1991: Linus makes first release of Linux.
1994: RedHat is founded.
1997: Apple buys NeXT for $427 million.
1997: Two guys start GNOME.
2001: First version of OS X released.
2002: GNOME HIG first released.

On top of the fact that OS X's codebase is a decade more mature, you have to consider the fact that no serious effort was put into Linux on the desktop until at least the late 1990s or early 2000s. Meanwhile, OS X, and NeXTStep before it, was always a desktop system foremost. The way I see it, desktop Linux is about 3-4 years old. GNOME 2.0 was the first Linux desktop designed to be a serious *product* (rather than a hobby), something slick for regular users. It was the first Linux desktop to have any sort of commercial support, and the first one to have a formal HIG. Given the timelines, I don't think that says anything bad about OSS developers at all!