updated 09:28 pm EDT, Mon June 23, 2014
OS X 10.6 was most popular OS version until 10.8 Mountain Lion arrived
The rate of decline in the number of users still clinging to OS X Snow Leopard has increased in the last three months, in part due to the continuing aging of machines capable of supporting it and natural turnover, but mostly due to the end of almost any further Apple support for the system -- including important security updates. The 2009-era OS version dropped four percent, the biggest quarterly decline since Mountain Lion came out, between March and May of this year, falling below 15 percent of active Macs.
Because it was the last operating system that still supported old PowerPC-based applications, many users retained 10.6.x for as long as possible to avoid upgrade costs associated with some applications, or to run one of the very few programs that didn't make the transition to Intel-based Macs. Certain versions of Intuit's Quicken and QuickBooks, older Adobe suites and the popular productivity tool AppleWorks were among the top programs users wanted to hang on to, despite various efforts at replacements or new versions.
Apple continued to include updates for Snow Leopard in certain areas -- particularly security, but also things such as Safari updates and printer/scanner drivers -- for five years, longer than it generally supports operating systems. OS X 10.7 Lion, which introduced a number of workflow changes such as Versions and auto-save, was embraced by many but took 10 months to top Snow Leopard in installed base. Although Apple has made no formal announcement ending Snow Leopard support, recent updates have been for 10.7 (Lion) and later.
Snow Leopard desktop
The introduction of 2012's Mountain Lion, which restored some features that had been altered in Lion and generally built upon Lion's most successful features, was quickly adopted by comparison. It became the most popular OS X installed version just five months after its introduction, a feat that was repeated when Mavericks came out in the fall of 2013 (some three months "late" by tradition OS X release standards). Five months after its introduction, OS X 10.9 Mavericks was the top choice of active Mac users, with Snow Leopard down to 18 percent support (tied with Lion by that point).
The final security update for Snow Leopard appears to have been issued last October, fixing various Java issues. Safari support was dropped in December, and printer/scanner driver support appears to have stopped in February of this year.
OS X Yosemite desktop
The company's iTunes (and by extension, QuickTime) software are still distributed for Snow Leopard, with the latest version available for 10.6.8 as well as later releases -- at least for the time being. However, all public support for security updates appears to have stopped, putting users who continue to use 10.6.8 on the Internet at some (small but growing) element of risk.
The OS version is now something akin to "Apple's XP," with loyal support among a segment of its audience, but gently declining in use due to natural attrition and updating to newer models, though Windows XP retains -- even now, 13 years after release -- a second-place rating among Windows users, with just over 25 percent support. The latest Windows 8 and 8.1 releases, by contrast, has just six percent share each, according to data from NetMarketshare.
To help those interested in updating, Apple continues to make available (for $20) a DVD of the final Snow Leopard release for Intel-based Macs. This can be used to update older machines that are using Leopard or early versions of Snow Leopard so that they can then utilize the Mac App Store to update their systems (if compatible) further, or gain compatibility with the latest iPhones and iPads through an updated iTunes. However, the DVD is seen as a stopgap measure, and is unlikely to remain available indefinitely.
Apple has been gently encouraging users of older machines to upgrade through various incentives, including the Snow Leopard DVD and the reduction in price of OS X upgrades. Mountain Lion was priced at $20 per copy, and Mavericks was offered at no cost to all for compatible machines -- which Apple took pains to stretch back to 2007 for some models, a deliberate move to encourage upgrading.
Mavericks (OS X 10.9) has generally been well-received, despite some continuing issues with certain graphics cards and Gmail integration in Mail. Apple has recently previewed the next major release, OS X 10.10 Yosemite, which will again be free and also supports all the older models that were able to run Mavericks -- though some of the newest features, such as Handoff, may not be available to the earliest supported machines, and units with early Intel graphics chipsets or less than 6GB of RAM may not reap the best experience. Yosemite is expected to be released in the fall.
Whether Apple will continue to make iTunes and QuickTime compatible with 10.6.8 for the sake of those running older iPhone and iPad models remains to be seen. The company does, however, seem to be increasingly eager to move Mac users to the fully 64-bit, all-Intel OS, graphics-prowess-dependent releases and the powerful recent-model machines that support them best (arguably those from 2010 and later).
If the 10.6.x decline continues at its present pace -- and there are clear indications that Apple has more equipment upgrades and new models in the pipeline for the second half of the year -- Snow Leopard will be down below 10 percent share by the end of the year. Users who wish to stick with Snow Leopard will need to be prepared for an increasing number of upgrades that they can't or should not apply if they want to maintain compatibility with old programs or peripherals, and that's before the subject of Internet security comes up. Apple has already said that its forthcoming iOS 8 will not support the iPhone 4 due to graphics constraints, a hint that iTunes support for 10.6.8 is probably (but gently) winding down. The writing, as they say, is on the wall.