Refined, not re-invented.

Mac OS X is renowned for its simplicity, its reliability and its ease of use. So when it came to designing Snow Leopard, Apple engineers had a single goal: to make a great thing even better. They searched for areas to refine, further simplify and speed up ? from little things like ejecting external drives to big things like installing the OS. In many cases, they elevated great to amazing. Here are just a few examples of how your Mac experience was fine-tuned.

A more advanced, more nimble Finder.

The Finder has been completely rewritten in Cocoa to take advantage of all the modern technologies in Mac OS X, including 64-bit support and Grand Central Dispatch. It?s more responsive from top to bottom, with snappier performance throughout the Finder. And it includes new features such as customisable Spotlight search options and an enhanced icon view that lets you thumb through a multipage document or watch a QuickTime movie.

Faster, more reliable installation.

Upgrading your Mac has never been easier. For Snow Leopard, the entire process has been simplified, streamlined and is up to 50 percent faster, yet more comprehensive and reliable.2 For example, Snow Leopard checks your applications to make sure they?re compatible and sets aside any programs known to be incompatible. In case a power outage interrupts your installation, it can start again without losing any data.

Another leap forward for QuickTime.

QuickTime X is the next-generation media technology that powers the audio and video experience in Mac OS X Snow Leopard. It includes a completely new QuickTime Player application with a clean, uncluttered design, a new trimming interface and easy uploads to YouTube and MobileMe. And it delivers more efficient media playback, HTTP-based live streaming and greater colour accuracy.

Safari 4

The latest version of Apple's blazing-fast web browser delivers up to 50 percent faster JavaScript performance and is more resistant to crashes than ever.
Use Top Sites to view your favorite websites at a glance, see which ones have been updated, and visit them in a click.
Complete search queries as you type with built-in Google Suggest.
Flip through full-page previews of your browsing history in Cover Flow the same way you flip through album art in iTunes.

New look, new features for Expos? and Stacks.

Expos? is refined and more convenient. It?s now integrated in the Dock, so you can just click and hold an application icon in the Dock and all the windows for that application will unshuffle so you can quickly change to another one. Expos? also has a whole new look. Windows are displayed in an organised grid, making it even easier to find what you?re looking for. And stacks ? Dock items that give you fast access to a folder of files ? are now scrollable, so you can easily view all items. You can also navigate through folders in a stack to see all the files inside it.

More secure than ever.

Another benefit of the 64-bit applications in Snow Leopard is that they?re even more secure from hackers and malware than the 32-bit versions. That's because 64-bit applications can use more advanced security techniques to fend off malicious code. First, 64-bit applications can keep their data out of harm's way thanks to a more secure function argument-passing mechanism and the use of hardware-based execute disable for heap memory. In addition, memory on the system heap is marked using strengthened checksums, helping to prevent attacks that rely on corrupting memory.

More reliable, higher-resolution iChat.

Having a video chat using iChat is more reliable and more accessible than ever in Snow Leopard.4 It includes technology to address many common router incompatibilities that can interfere with connections. And if iChat can?t make a direct connection, it will use the AIM relay server to create a successful chat session.

Now more people can have high-resolution, 640-by-480-pixel video chats, because the technical requirements are less demanding: You need only one-third the upstream bandwidth previously required ? 300 Kbps instead of 900 Kbps. And finally, iChat Theater now offers 640-by-480 resolution, four times greater than before.

The 64-bit transition.

The entire computing industry is moving from 32-bit to 64-bit technology, and it?s easy to see why. Today?s Mac computers can hold up to 32GB of physical memory, but the 32-bit applications that run on them can address only 4GB of RAM at a time. 64-bit computing shatters that barrier by enabling applications to address a theoretical 16 billion gigabytes of memory, or 16 exabytes. It can also enable computers to crunch twice the data per clock cycle, which can dramatically speed up numeric calculations and other tasks. Earlier versions of Mac OS X have offered a range of 64-bit capabilities. Now Snow Leopard takes the next step in the transition from 32-bit to 64-bit.

Ready for the future.

The 64-bit support in Snow Leopard makes Mac OS X completely ready for whatever computing enhancements might arrive in the future. For example, Snow Leopard is ready to support up to 16 terabytes of RAM ? about 500 times more than today?s Mac computers can accommodate. That may sound like more RAM than you?ll ever need, but who can predict the requirements of high-performance computers in the future? Mac OS X Snow Leopard comes prepared for anything.