Apple has sold more than six million copies of Mac OS X 10.7, better known as Lion, since its debut in late July, CEO Tim Cook revealed yesterday.

The figure is 80% higher than sales of the previous operating system, Snow Leopard, during a similar stretch in 2009, Cook added during the early minutes of a presentation at the company's Cupertino, Calif. campus to unveil the new iPhone 4S smartphone.

Cook also took a shot at rival Microsoft and its Windows 7 operating system, saying that Lion was powering 10% of all Macs within two weeks of release, compared to Windows 7 taking 20 weeks to match that same level of penetration.

What Cook omitted was Microsoft's much larger share of the operating system market, and thus the need for Windows 7 to sell a much larger quantity of copies to reach a 10% share of all Windows machines.

In September, Microsoft boasted that it had sold more than 450 million copies of Windows 7 since that edition's 2009 debut.

According to web metrics company Net Applications, Lion was running about 22% of all Macs that went online last month, while its immediate predecessor, Snow Leopard, accounted for 55% of Macs and 2007's Leopard powered about 18%.

Windows 7, meanwhile, finished August with a 35% share of all Windows PCs.

During August, the first full month of its availability, Lion's share of the total Mac OS X market was approximately 17%.