U.S. District Court Judge William Alsup ruled on Friday that Psystar was guilty of copyright infringement against Apple, according to Natalie Weinstein of CNET. The whole case revolves around Apple’s Mac operating system. Unlike Windows or Linux, which you can install on whatever hardware you like, Apple only wants the Mac OS to belong to Apple computers.

That hasn’t stopped hundreds of enterprising hackers from building their own machines and installing Mac OS X. But because Apple designed the operating system with a particular hardware and BIOS configuration in mind, the OS doesn’t always work properly on an unauthorized machine. And the process of installing a non-native operating system is complicated and can require a lot of troubleshooting — it’s not something the computer novice should attempt.

That’s where Psystar stepped in. The fact that hackintoshes (the common name for a PC running the Mac OS) exist shows that people want computers running the Mac OS but they don’t want an actual Apple computer. Maybe they don’t like Apple’s product design, or perhaps they feel that the Mac line of computers is too expensive. In 2008, Psystar began to sell PCs running the Mac operating system. The company took care of the tricky process of installing the OS on non-Apple hardware (though Psystar also explained that the computer might not always behave as it should).