Mac OS X 10.0 was released five years ago today, on March 24th, 2001. To me, it felt like the end of a long road rather than a beginning. At that point, I’d already written over 100,000 words about Apple’s new OS for Ars Technica, starting with the second developer release and culminating in the public beta several months before 10.0. But the road that led to Mac OS X extends much farther into past—years, in fact.