Primary source for this information comes from Apple.com.
Beginning August 28th 2009, every new Mac computer came with Mac OS X Snow Leopard pre-loaded. If your Intel-based Mac was running Mac OS X v10.5 Leopard, Apple offered an upgrade to Mac OS X v10.6 Snow Leopard for $29 US. Otherwise, the user had to purchase the Mac Box Set, which included Mac OS X v10.6 Snow Leopard; iLife, with the latest versions of iPhoto, iMovie, GarageBand, iWeb, and iDVD; and iWork, Apple's productivity suite for home and office including Pages, Numbers, and Keynote for $169 US.
To use Mac OS X v10.6 Snow Leopard, your Macintosh needs:
Mac computer with an Intel processor
1 GB of memory
5 GB of available disk space
DVD drive for installation
Some features require a compatible Internet service provider; fees may apply.
Some features require Apple's MobileMe service; fees and terms apply.
Check out Apple Profile Specs for an overview of the supported hardware for Mac OS X.
Feature-specific requirements
Time Machine
requires an additional hard drive or Time Capsule (sold separately).
Photo Booth
requires an iSight camera (built in or external), USB video class (UVC) camera, or FireWire DV camcorder. Backdrop effects when using a DV camcorder require fixed focus, exposure, and white balance.
Boot Camp
requires Windows XP with Service Pack 2 or Windows Vista (sold separately).
Screen sharing
in iChat and the Finder requires a 128-Kbps Internet connection (300 Kbps recommended).
DVD Player
requires a 1.6 GHz processor or faster for improved deinterlacing.
iChat
Audio chats require a microphone and a 56-Kbps Internet connection.
Video chats require an iSight camera (built in or external), USB video class (UVC) camera, or FireWire DV camcorder; and a 128-Kbps upstream and downstream Internet connection.
Backdrop effects when using a DV camcorder require fixed focus, exposure, and white balance.
Some iChat features offer better performance and quality with higher system capabilities.
Exchange Support
requires Microsoft Exchange Server 2007 Service Pack 1 Update Rollup 4. Auto-setup requires enabling the Autodiscovery feature of Microsoft Exchange Server.
QuickTime X movie capture
requires iSight camera (built-in or external), USB video class (UVC) camera, or FireWire DV camcorder.
QuickTime H.264 hardware acceleration
requires a Mac with an NVIDIA 9400M graphics processor.
Developer tools
require 1 GB of memory and an additional 3 GB of available disk space.
OpenCL
requires one of the following graphics cards or graphics processors:
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