Snow Leopard - The Arstechnica Review

In June of 2004, during the WWDC keynote address, Steve Jobs revealed Mac OS X 10.4 Tiger to developers and the public for the first time. When the finished product arrived in April of 2005, Tiger was the biggest, most important, most feature-packed release in the history of Mac OS X by a wide margin. Apple's marketing campaign reflected this, touting "over 150 new features."

All those new features took time. Since its introduction in 2001, there had been at least one major release of Mac OS X each year. Tiger took over a year and a half to arrive. At the time, it definitely seemed worth the wait. Tiger was a hit with users and developers. Apple took the lesson to heart and quickly set expectations for the next major release of Mac OS X, Leopard. Through various channels, Apple communicated its intention to move from a 12-month to an 18-month release cycle for Mac OS X. Leopard was officially scheduled for "spring 2007."L33tdawg: I just upgraded this morning and despite having to decrypt my PGP WDE drive I ended up having to wipe and do a fresh install anyway! Thankfully Time Machine worked brilliantly and all my data was restored without any fups :)