GMSV references interesting market share trends for MSFT IE and the Windows OS. Use of IE is falling dramatically, apparently due to competition from Firefox, though Apple’s Safari plays a secondary role.

Last month, Microsoft’s Internet Explorer was used by 68.15 percent of the Web surfers monitored. In January 2008, that figure was 75.47 percent; in January 2007, it was 79.98 percent.

The slippage in Windows market share is less dramatic but far more important (bigger business, wide marketplace implications if the trend continues).

The Net Applications stats on operating systems were no more encouraging for Microsoft. In January 2007, 93.33 percent of the Web travelers monitored were running Windows; last month, that figure was down to 88.68. Across the same period, the Mac share rose from 6.22 percent to 9.63.