Firefox's dramatic success in the browser market appears to be slowing, according to the latest figures.

After an initial surge with the release of the first full version in November, the pace at which the open-source browser is winning market share has slowed down. It now holds 5.7 percent of the market, according to analyst firm WebSideStory. Microsoft's Internet Explorer may have seen its figures slip but it still dominates with a remarkable 89.9 percent of the market.

According series of figures from, give Firefox an 8.45 percent share with Explorer boasting 87.28 percent.

However, the speed at which Firefox is gaining market share has slowed down, WebSideStory said. Firefox's market share grew 15 percent over the last five weeks, compared to growth of 22 percent in the period between December and January. From November to December, it was growing at 34 percent.

Firefox's initial aim was to reach a 10 percent market share by the middle of 2005 and it is set to reach that goal - but only at the end of the year, warned WebSideStory. "Growth in Firefox’s usage has slowed slightly since its big surge in November. This is probably to be expected as we move beyond the early-adopter segment," WebSideStory CEO Jeff Lunsford said. "Growing concern over potential security holes in the browser might be another factor to consider."

The Mozilla Foundation, the distributor of Firefox, last week warned of serious security flaws in the browser and released an update. In an about face two weeks ago, Microsoft said it would release a test version of Explorer 7.0 later this year. Previously, Microsoft had said it would not offer a browser upgrade until the next version of Windows ships in late 2006.