A patched version of the Mac operating system that enables Mac OS X to run on a regular PC, not a Mac computer from Apple. Also called a "Hackintosh," an OSx86 machine is an illegitimate Mac clone that came about after Apple switched to Intel CPUs, starting in 2006. OSx86 uses the Mac OS X operating system modified with software patches from various sources, and new patches must be made available with each new version from Apple. The x86 PC's BIOS must also be updated to support the Apple's boot interface (see UEFI). In addition, regular Apple software updates cannot be applied to most OSx86 machines.

In 2008, Florida-based Psystar began shipping an OSx86-based PC under its Open Computer brand. It offered a PC that booted into Mac OS X at a considerably lower price than a genuine Mac. Not met with enthusiasm by Apple, it promptly launched a lawsuit against Psystar for licensing violations. See Mac clone.