After Psystar countersued Apple a month ago for anticompetitetive business practices (read here). Apple’s attorneys now respond on 23 pages. Apple’s argumentation in short: Psystar violates Apple’s license agreement when putting Mac OS X on Psystar’s OEM computers.
In the paper Apple tries to circumvent the whole monopoly issue by argueing that there is no specific Mac OS X market, but an Apple Computer market. And since there is no specific market for the sole operating system, Apple is no monopolist. Rather than having a Mac OS X operating system market, there is a market for computers and in this market Apple Computers compete with other computers. Apple sums up that Psystars charges need to be rejected, because Apple as a company cannot be forced to help their competitors and thus weakening their own market position.
You may read the whole argumentation here at ZDNET. They released the whole 23 pages as a PDF.
This whole topic remains fascinating. From a technical point of view we would not follow Apple’s argumentation here, because of a simple fact. Mac OS X is heavily based on lots of open source parts from the Linux and GNU worlds. And the Mac OS X’s kernel Darwin was and still is available for x86 based PCs aswell. This might mean by releasing the kernel as a stand alone version, they implicitly admit that the operating system is only artificially bound to the hardware. You may find more some technical notes in our recent article here (see VII. Modify startup script) and on the wiki of the Chaos Communication Congress 2007.