Apple released Mac OS X 10.6.3, the latest update to Snow Leopard, on March 29. The update includes not only several tweaks to applications such as Time Machine, but also a security component, leading Apple to recommend it for all current users of Snow Leopard.
According to Apple, the update is meant to address a number of issues, including reliability of "certain third-party USB devices," photo screen savers, QuickTime X and printers; apparent color issues in iMovie with HD content; OpenGL-based application compatibility; and DNS server ordering "as specified in Network Preferences and DNS reliability." It patches problems related to AirPort and wireless networking, Directory and File Services, iCal, Mail, Mobile Accounts, MobileMe, Parental Control, Rosetta, System Imaging, Time Machine, and Xsan.
And it changes the Daylight Savings Time rules for areas such as Argentina, Fiji, Pakistan and Antarctica. This is important if you live in Argentina, Fiji or Pakistan or are probably the only person using a MacBook on the frozen wastes at the bottom of the world.
More information about the update, along with Apple's warning that "you may experience unexpected results if you have third-party system software modifications installed," can be found on this Apple support site.
Apple's two previous updates to Snow Leopard, in September and November, also included a variety of tweaks. Mac OS X 10.6.1, for example, attempted to address a range of stability, security and compatibility issues. Its original version shipped in August 2009 and was initially priced at $29 for Intel-based Macs already running Leopard-unless the user purchased a qualifying system after June 8, in which case the upgrade to Snow Leopard cost $9.95. At the time, some pundits perceived Apple's pricing as a way to steal some thunder from Microsoft's ramp up to the release of Windows 7.
Fundamental changes between Leopard, or Mac OS X 10.5, and Snow Leopard included a rewrite of the Finder in 64-bit Cocoa to speed up fundamental processes such as startup, installations and shutdown. The newer operating system version also left a smaller OS footprint on the disc, effectively freeing around 7GB of memory.
Within two weeks of Snow Leopard's release, research firm NPD Group found that the operating system was outselling Apple predecessors Leopard and Tiger by respective 2-to-1 and 4-to-1 margins.
This newest update comes just as Apple prepares for the April 3 release of the WiFi version of its long-awaited iPad, a tablet PC running on a modified version of the iPhone OS, and which has enjoyed strong presales over the previous few weeks. Versions of the iPad with both WiFi and 3G will supposedly be released later in April.