As noted by Macworld UK, Apple's Mountain Lion has clawed its way to the top of the Mac OS jungle. It was released on July 25, 2012 and as of this past December accounts for 32 percent of all Macs online, according to Net Applications, a web-measurement film that tracks OS usage by visitors to 40,000 websites.
That 32 percent represents a 3 percent increase for the OS from November when it accounted for 29 percent of all Macs online. That gain came mostly from OS X 10.7 Lion, which sank from 30 percent to 28 percent. Mountain Lion also stole one percentage point from OS X 10.6 Snow