Propelled by the release of its Version 2.0 in October, the free Firefox Web browser saw almost a 50% increase in use during 2006, according to one Web measurement firm.

The open-source Firefox browser was used by 14% of computers online at the end of 2006, according to Net Applications. That was 46% higher than its 9.6% share of the browser market at the beginning of the year.

The biggest loser was Microsoft's Internet Explorer, which also released a new version, Internet Explorer 7, last year. Even so, its market share fell to 79.6% from 85.1% at the start of 2006.

Apple Computer's Safari Web browser rode increased sales of Mac computers to finish the year with 4.2% of the market, up from 3.1% at the beginning of 2006. Safari is only available on Apple hardware running Mac OS X.

The Opera Web browser also grew its share to 0.9% of the market from 0.6%, after signing deals with cell phone makers and game console makers such as Nintendo to have the software bundled with those devices.

AOL's Netscape was, like Internet Explorer, also a loser. It started the year with 1.24% but saw its share of the market fall to 0.9%.