Firefox market share on a rollercoaster ride

Mozilla's Firefox lost market share to Internet Explorer in September, after recovering in August: is this a sign of stability or of decline?

After posting its first decline in market share since launch in July, only to recover in August, Mozilla's Firefox browser saw its lost share of the browser market drop again in September, according to one monitoring firm.

According to figures produced by the Web applications provider NetApplications, Firefox had 7.55 percent share of the browser market in September, against 86.9 percent for Internet Explorer.

Until June this year, Firefox's market share had grown steadily, month on month, from 2.69 percent in October 2004 to a peak of 8.71 percent in June. But in July, Firefox's share dropped to 8.07 percent, rebounded to 8.27 percent in August, before dropping again. In the meantime, Microsoft's Internet Explorer share has hovered betweem 86 percent and 87 percent.

At this stage it is difficult to assess whether Firefox is in a period of stability or long-term growth or whether, in fact, this month's figures are just a blip in a continuing period of growth.

After its long period of growth – and positive publicity – Firefox has recently been hit by a string of concerns about its security. However, this has been balanced by continuing concerns over several IE security flaws over the same period, including a flaw in the way IE handles JPEGs and a bug that could allow arbitrary code execution.

Security firm Symantec caused a storm last month when it pointed out that Mozilla browsers were having flaws found in them at a greater rate than IE.

Information Week  reported that Firefox's market share may have been artificially inflated in the past because another browser, Netscape 8.0, had typically been identifying itself as Firefox. The latest version of Netscape does not do this.