Following in the wake of its record quarterly profit, Apple has released some more numbers on adoption of Mac OS X Lion. After nine months, 40 percent of users are on the OS, for a total of 26 million copies shipped and a total Mac install base of 66 million. That's quite a growth over WWDC 2011, when Apple announced an install base of around 54 million. For Lion, it's also a much faster adoption rate than Microsoft enjoys with Windows 7, as Apple demonstrated for us with a slide showing the two operating systems at roughly similar adoption levels among users despite Windows 7 having been out for nearly three times as long. Of course, Windows also has a much bigger market share, so those are percentages in the chart, not numbers. Lion is now being superseded by Mountain Lion, so Apple's going to have another round of updates for us soon.