Depending upon where you look for results, Mac OS X Lion is running on 30 or 40 or whatever percent of machines in the Mac installed base. All agree that this number keeps climbing.
Chitika Insights, an online data analytics company, reported recently that Mac OS X Lion has a 30.47 percent share, while Mac OS X 10.6 (Snow Leopard) and 10.5 (Leopard) have 47.48 percent and 16.4 percent shares, respectively. The Preview of the forthcoming Mountain Lion OS due in the summer has a 0.06 percent share the site reports (it would be unreasonable for anyone to think it would would have any measurable number).
According to Net Applications' Net Market Share counter, Lion has almost caught up to Snow Leopard. Its share figures are Snow Leopard 43 percent, Lion 40 percent, Leopard 14 and Tiger 14 percent. Mac OS X Mountain Lion and the mysterious Other versions have zero percent.
The strength of Snow Leopard isn't so much of a surprise. There are still good reasons not to upgrade. A number of important applications require the Rosetta PPC translation technology, which is not available under Lion. Rosetta is required by a number of applications used in professional Adobe workflows as well as Quicken for Mac.
While Intuit a few weeks ago released Lion Compatible Quicken Mac 2007, which should work on Mac OS X Lion, it appears by the comments in the support discussions that the progress is bumpy and the software is crashing for many users. This isn't the best experience for any program but especially one for a productivity app.
I still receive one or two letters a week from folks who upgraded to Lion and didn't get the message about Quicken. If you are running Quicken for Mac, don't upgrade to Lion unless you have a spare machine that can run Snow Leopard or Leopard. I don't recommend running Snow Leopard as a separate boot on a Lion machine.
Aside from the Mac OS, Net Applications says that the iOS platform has a 60 percent share of the mobile market. Java ME and Symbian are the big losers over the course of the past year: Java fell from 24 percent to 15.86, and Symbian fell from 6.3 percent to 2.77 percent. Good for Apple and Google (Android).