Firefox 3.5 is off to a storming start, with nearly five million downloads just 24 hours after its launch.

By 5pm today the browser looks on course to hit five million downloads at least. While the download figure does not match the browser's last record-breaking launch, when more than eight million people downloaded Firefox 3 in its first 24 hours, the figures are still impressive by the standards of the industry.

The US is currently leading the download race, with over 1.1 million copies drawn down from Mozilla's servers. In the UK, the figure stands at 170,000, which is relatively high, although outpaced by Germany's 540,000 downloads and France with around 225,000.

So far there is little sign of servers being overloaded. Some users reported problems in the first few hours after the release, but according to Mozilla's real-time download counter all servers are operating well within capacity limits.

While the download figures do not match the previous 3.0 release they compare well to earlier versions. Firefox 2.0, for example, had around 1.5 million downloads at the end of its first day.

Firefox 3.5 is the first mainstream browser to offer full HTML5 support and includes a private browsing feature, which was originally popularised by Microsoft's Internet Explorer 8.0.