Mac OS X 10.6 “Snow Leopard” é um sistema operacional Apple sucessor do versão 10.5 “Leopard“. Apple CEO Steve Jobs anunciou o Snow Leopard na Apple Worldwide Developers Conference (WWDC) em 8 Junho de 2008.[1] Snow Leopard irá ser vendido em setembro de 2009 e uma atualização disponível para os usuários do Leopard por $29. Usuários do Tiger users poderão atualizar com o Mac Box Set, um pacote irá incluir o Snow Leopard, iLife ’09, e iWork ’09.

A atualização para Mac OS X irá ser focada em performance, eficiência e reduzir o consumo de memória, em vez de novas funcionalidades para o utilizador final. Será o primeiro Mac OS desde o System 7.1.2 a não suportar a arquitetura PowerPC como a Apple está focada na linha atual de produtos baseado em Intel. [1] Developer previews foi entregue aos desenvolvedores.

Melhorias e inovações

A Apple afirmou que o Mac OS X “Snow Leopard” incluirá as seguintes alterações e melhorias:

Refinamentos para interface do usuário

Sem grandes revisões gerais para a interface existente no Leopard, a Apple tem re-escrito o Finder em Cocoa para tirar proveito de outras melhorias no novo processo Snow Leopard. Estes incluem:

* Stacks agora permitem visualizar uma subpasta sem lançar Finder. também foram modificados para incluir barras de rolagem-pastas com muitos arquivos, e ligeira mudança de interface, agora com uma borda translúcida.
* Faster PDF and JPEG Icon refreshes.
* PDF and movie playing in the Finder icon view.
* Seleção de coluna de texto em documentos PDF, analisando a página.
* Inicialização mais rápida, desligar mais rápido, instalaçao mais rápido, Extabilização de Time Machine backup e conexão.
* Smaller OS footprint on disk.

Suporte para o Microsoft Exchange

Mac OS X Snow Leopard will include out-of-the-box support for connecting to Microsoft Exchange 2007 servers for access through Mail, Address Book , e iCal. This step makes Macs to be the first computers to be bundled with Exchange support.

Endereçamento 64-bit

Mac OS X Snow Leopard and all Mac OS 10.6 built-in applications have been rebuilt to leverage the 64-bit addressing space, since Apple has started shipping each Mac as a 64-bit system. 64-bit systems address the current limitation of 4 GB RAM per application to increase to 16 billion GB or 16 exabytes per application. This speeds up Quicktime, Safari’s Javascript engine and PDF viewing by 20-50%.

64-bit applications also increase system security compared to 32-bit systems due to the availability of more advanced security techniques to safeguard against attacks. They use a more secure function-passing mechanism and usage of hardware-based execute disabled for heap memory. The system heap now uses strengthened cryptographic signatures to prevent memory-corrupting attacks.

Grand Central Dispatch

Grand Central Dispatch utilizes multiple processor cores now in every new Macintosh for more efficient performance. Due to the technical difficulties involved in making multi-core-optimized applications, the majority of applications do not effectively utilize multiple processor cores. As a result, processing power is often “wasted”. Grand Central Dispatch includes APIs to help programmers efficiently utilize these cores for parallel programming.

Grand Central Dispatch shifts thread handling focus to itself rather than leaving it to specific applications to distribute jobs evenly across cores and clears up unused memory created by inactive or old threads to achieve maximum performance. Apple is also releasing APIs for Grand Central Dispatch for developers to use in their applications and also to analyze specific blocks of code running on Grand Central Dispatch.

OpenCL

OpenCL (Open Computing Language) addresses the power of Graphical Processing Units to leverage it in any application, and not just for graphics-intensive applications like 3D games. OpenCL automatically optimizes for the kind of graphics processor in the Mac, adjusting itself to the available processing power. OpenCL provides consistent numeric precision and accuracy, fixing a problem that has hampered GPU-based programming in the past.

OpenCL is a C-based programming language with a structure is already familiar to Mac OS X programmers, who can use Xcode developer tools to adapt their programs to work with OpenCL. Only the most process intensive parts of the application need to be written in OpenCL C without affecting the rest of the code. Apple has released OpenCL as an open standard that has been supported by AMD, Intel and nVidia.

It serves a similar purpose to Nvidia’s C for CUDA and Microsoft’s Direct3D compute shaders.

QuickTime X

QuickTime X, the next version of QuickTime player, builds on the media technologies in Mac OS X, such as Core Audio, Core Video, and Core Animation, to deliver enhanced playback, greater efficiency, and higher quality. Apple has redesigned the QuickTime user interface to resemble the current QuickTime full-screen view, where the entire window plays only the video and controls fade in and out as needed.

QuickTime X supports for HTTP live streaming. Unlike other streaming technologies, HTTP live streaming uses the HTTP protocol. Thus, QuickTime X streams audio and video using any web server instead of a special streaming server, and it works reliably with common firewall and wireless router settings. HTTP live streaming is designed for mobility and can dynamically adjust movie playback quality to match the available speed of wired or wireless networks.

QuickTime X uses Mac OS X technologies such as Cocoa, Grand Central Dispatch, and 64-bit computing to deliver higher performance and enables QuickTime Player to launch up to 2.8x faster than QuickTime. QuickTime X also takes advantage of ColorSync to provide high-quality color reproduction.

Sistema Comum de Impressão UNIX

CUPS (the printing system in Mac OS X and Linux) will be updated to version 1.4 which provides improved driver, networking, and Kerberos support along with many performance improvements. CUPS 1.4 is also the first implementation of the Internet Printing Protocol version 2.1.

Fonte: Wikipedia.