In Depth Mac OS X Leopard Review
ArsTechinca's John Siracusa posts an in depth review of Leopard, which refreshingly goes beyond the typical superficial glance at features. In fact, portions of the review may be too technical for the many readers, but does point out several under-the-hood improvements in Mac OS X 10.5 that may not be immediately obvious. Indeed, Siracusa summarizes the 17 page review:
As I've learned more about Leopard, it's become increasingly clear where, exactly, those two-and-a-half years of development time went. Leopard is absolutely packed with improvements. It seems that not a corner of the OS has gone untouched.
Perhaps that's not as clear to the casual user who just sees the surface changes and the major new features in Leopard. But even in that case, there's more than enough to recommend it. if you're wondering whether you should upgrade to Leopard, the answer, as it's been for every major revision of Mac OS X, is yes.
That being said, the review does touch on some aspects of Leopard's superficial changes, including the new standardized look of windows, changes in Finder behavior and the impracticality of Apple's current Stacks implementation:
There's just not enough room in a single Dock tile for a stack of icons to convey any meaningful information. Only the top one, two, maybe three items have any visual impact. And those few items may be misleading (e.g., the home folder appearing to be the Desktop folder) or completely generic (e.g., the Pictures and Movies folders showing up as plain folder icons.) Seriously, Apple, this is a bad idea.
Siracusa is, however, enthusiastic about Time Machine ("people will actually use") and describes steady and significant improvements in Mac OS X's performance and responsiveness. Leopard's kernel is also said to be better about scheduling processes, allowing you to make better use of multi-core CPUs.
Of technical interest, the article explores Leopard's implementation of DTrace to assist in debugging, the full transition to 64-bit, and the full adoption of Cocoa:
The last vestiges of the original Macintosh API are finally being put to rest. They've done their job and are being given a decent burial, I think. A slow, almost natural transition. Bugs will be fixed in the 32-bit Carbon APIs, of course, but no new features will be added. All new GUI APIs in Leopard and future Mac OS X releases will be added as Cocoa-only APIs.
This transition, of course, affects some of Apple's biggest developers (such as Microsoft and Adobe) who have a large library of Carbon code for their applications.
A lot of groundwork has also been laid towards implementing resolution independence, though even Apple's implementation across their own applications is thus far inconsistent. Full Resolution Independence support as a user-accessible feature is not expected until 2008. But this should allow Apple to introduce super-high-resolution displays and provide a consistent user experience.
The full review is worth reading if you have an interest in Mac OS X Leopard.