Introduction

At the end of my Mac OS X 10.4 Tiger review, I wrote this.

Overall, Tiger is impressive. If this is what Apple can do with 18 months of development time instead of 12, I tremble to think what they could do with a full two years.

That was exactly two and a half years ago, to the day. It seems that I've gotten my wish and then some. Mac OS X 10.5 Leopard has gestated longer than any release of Mac OS X (other than 10.0, that is). If I had high expectations for 10.5 back in 2005, they've only grown as the months and years have passed. Apple's tantalizingly explicit withholding of information about Leopard just fanned the flames. My state of mind leading up to the release of Leopard probably matches that of a lot of Mac enthusiasts: this better be good.

Maybe the average Mac user just expects another incrementally improved version of Mac OS X. Eighteen months, two and a half years, who's counting? Maybe we enthusiasts are just getting greedy. After all, as Apple's been so fond of touting, there have been five releases of Mac OS X in the time it's taken Microsoft to deliver Windows Vista.

But far be it from me to use Microsoft to calibrate my expectations. Leopard has to be something special. And as I see it, operating system beauty is more than skin deep. While the casual Mac user will gauge Leopard's worth by reading about the marquee features or watching a guided tour movie at Apple's web site, those of us with an unhealthy obsession with operating systems will be trolling through the internals to see what's really changed.

These two views of Leopard, the interface and the internals, lead to two very different assessments. Somewhere in between lie the features themselves, judged not by the technology they're based on or the interface provided for them, but by what they can actually do for the user.

This review will cover all of those angles, in varying degrees of depth. Like all other Mac OS X releases before it, Leopard is too big for one review to cover everything. (After all, Tiger's internals alone can fill over 1,600 printed pages.) As in past reviews, I've chosen to delve deeply into the aspects of Leopard that are the most interesting to me while also trying to provide a reasonable overview for the non-geeks who've decided to take the plunge into an Ars Technica review. (Hi, Mom.)

Okay Leopard, let's see what you've got.