Apple plans to release a version of its forthcoming Safari 3 browser for Windows XP and Vista.

Apple chief executive Steve Jobs revealed the planned October release in his opening keynote at the World Wide Developer Conference in San Francisco on Monday. A public beta has been made available on Apple's website.

The company claims that Safari is "up to two times faster" than Internet Explorer and one and a half times faster than Firefox. Performance was measured in HTML rendering, JavaScript performance and the time it takes the application to launch.

"What we've got here is the most innovative browser in the world. But we've also got the fastest browser on Windows," Jobs told delegates at the developer event.

Expansion of the application to Windows aims to enlarge Safari's market share. The browser currently runs on 4.8 per cent of the world's computers, according to data gathered by net traffic measurement vendor NetApplications.

Microsoft's Internet Explorer leads the pack with 78.7 per cent, followed by Mozilla's Firefox with 14.5 per cent.

Most of Safari's functionality is similar to that of Internet Explorer and Firefox. The browser offers pop-up blocking, tabbed browsing and an integrated RSS reader.

But Safari offers some unique features, such as resizable text input fields, the option to instantly return to a previously set anchor point in the browser history such as a search results page, and a private browsing mode where the computer does not log user information such as search queries.

Apple lists security on the bottom of the software's feature list, but argues that Safari will enable "worry-free browsing on any computer".

Security has traditionally been a big selling point for Firefox, as Internet Explorer has suffered a large number of vulnerabilities that allowed for so-called drive-by downloads where attackers infect a computer simply by luring users to a specially crafted website.

Beating the browser security drum, however, could have been a risky move, as security flaws are not a Microsoft monopoly.

Firefox has suffered from flaws that enabled drive-by downloads and, although no such attacks are known to have hit OS X, Apple has repaired numerous vulnerabilities in the browser over the years.

• Shaun Nichols contributed to this story from Apple's World Wide Developer Conference in San Francisco