For all its gains since then, however, Mountain Lion has not kept pace with the uptake trajectory of Apple’s last two editions, OS X 10.6, aka Snow Leopard, and OS X 10.7, better known as Lion.
Mountain Lion adoption has been quick for my customers, with slightly more than 50% of SpamSieve users now running 10.8. (25% are on 10.7, 19% are on 10.6, and less than 4% are on 10.5.)
Mountain Lion’s gains were again more at the expense of Lion than Snow Leopard, although the gap narrowed in October.
Snow Leopard has lost more than half its share of all Macs since Lion’s appearance over a year ago, but so far it has been resistant to Mountain Lion’s call to upgrade. In each of the last two months, for example, Snow Leopard’s losses were less than its 12-month average.
The chart of the Net Applications data is striking. It’s also interesting that a higher percentage of Macs are running Snow Leopard now than were when Snow Leopard was as old as Mountain Lion currently is. I’m not sure what’s behind this, although people seemed to agree last week when I noted Snow Leopard’s reliability.