Mac OS X is the operating system included with all Apple Macintosh computers. Mac OS X (pronounced OS "ten") is the tenth major version of Apple's operating system. Mac OS X versions are named after big cats. The current version as of this writing is 10.6, codenamed Snow Leopard. Apple has anounced the next version (10.7, Lion) with an expected release date to be in the second quarter of 2011.

Apple has also created a specialized version of Mac OS X that runs their smaller consumer devices. This specialized version is called iOS and runs on the iPhone, iPod Touch, iPad, and 2nd generation Apple TV.

Mac OS X is a 64-bit operating system. Nearly all of the built-in system applications provided by Apple are 64-bit applications. This includes Finder, Mail, Safari, iCal, and iChat. Mac OS X is also backwards compatible with 32-bit applications.

Mac OS X Versions


  • Mac OS X doesn't get PC viruses.
  • Mac OS X has built-in support of Adobe's PDF format as well as Micorsoft Office's Word, Excel, and PowerPoint documents.
  • The most recent version of Mac OS X (Snow Leopard) also includes out of the box compatibility with Microsoft Exchange Server 2007. This includes support of Exchange e-mail, calendar, and contact connectivity.
  • Mac OS X comes with automated backup software called Time Machine. It works with an external drive to backup and restore data. With the Time Machine software you can browse and restore multiple versions of a file that has been deleted or overwritten.
  • Mac OS X allows you to dual boot your your Mac with OS X and and Windows XP using included software called Boot Camp. (This assumes you're using an Intel-based Mac which would be any Mac produced after Jan 2006 when Apple transitioned from Power PC to Intel processors).
  • Snow Leopard is the first Mac OS X version in which nearly all built-in system applications run as 64-bit processes on capable hardware. This includes Finder, Mail, Safari, iCal, and iChat among others.
  • OS X is based on the proven and secure UNIX foundation.
  • OS X can run Apple's iLife and iWork software suites.
  • There is only one version of the operating system and the upgrade only costs $29.
  • This one version supports both 64-bit and 32-bit applications.