Apple and Psystar have been embroiled in litigation for quite a while now. At the core of the dispute: Psystar modifies Apple's operating system software so that it can run on its clone machines. It then sells its computers with Mac OS installed to, well, anybody who wants one. As you can imagine, this does not make Apple happy.

Anybody familiar with The Great Clone Crackdown of 1997 will tell you that Apple likes to keep a very tight grip on any device that presumes to run its software. Apple points out that Windows machines are a mishmash of often conflicting hardware and suffer from quirks and errors and incompatibilities that such a set up can bring.

So Apple's cadre of lawyers descended quickly on Psystar. In July of last year, the company sued Psystar for copyright and software licensing violations, quickly amending its lawsuit to additionally charge Psystar with violations of the Digital Millennium Copyright Act (DMCA).

And there was much lawyering.

More than a year later, now that discovery has been completed, the two parties have each filed for summary judgment, which, in effect, asks the judge to rule in favor of the filing party because enough evidence has been shown that either makes or breaks the lawsuit.

Psystar's argument, and the one covered in its motion, somewhat relies on the "first sale doctrine" which says that any purchaser of a copyrighted product can then take that lawfully-made copy and sell it, so long as no additional copies can be made. For its part, Apple says that when one "purchases" its OS, you are only purchasing a license to use the product. Its Software Licensing Agreement (SLA) quite clearly states [PDF link to Snow Leopard SLA] that the user cannot modify the software to run on a non-Apple system.

The idea that what you are purchasing is a license to use the product is pretty commonplace among software manufacturers, because, the argument runs, you can cut any software company's profits off at the knees if every purchaser became an owner with free rein to redistribute the software. Apple states that no software company in its right mind would put the money into research and development of any software product at all if that were the end result of bringing its product to market. Groklaw suggests this could have ramifications for FOSS and and the GPL.