Why was it not FreeBSD but Linux that became the most popular open source Unix-like operating system? Richard Hillesley traces the history of FreeBSD and examines how FreeBSD, and Linux, their different cultures and preferred licenses affected the open source world. "The BSD hackers have an aphorism that speaks some truths, which says: 'BSD is what you get when a bunch of Unix hackers sit down to try to port a Unix system to the PC. Linux is what you get when a bunch of PC hackers sit down and try to write a Unix system for the PC.' This aphorism speaks of a difference in the cultures that is greater than the words contained within it."