San Francisco - Microsoft on Wednesday unveiled a trial version of a new Internet Explorer designed to fight the growing challenge from Firefox.

But the new browser from the giant software company won't have it easy. Developers for the open-sourced Firefox released a trial version of a new application for the internet, Ubiquity, which makes it easier to access and share information that combines intuitive commands with browser functionality.

Microsoft's new Internet Explorer showed off improved privacy and security features that give users greater control over their browsing history, "cookies" and other data.

The browser boasts "InPrivateBrowsing," which allows users to surf the visit being logged in the browser history, and "InPrivateBlocking" that prevents sites gathering information about their visit.

It also includes a browsing tool called an "accelerator," which allows users to highlight text on a Web site and access a variety of functions, including different search engines, language translation or map displays.

Ubiquity offers a similar service but with a much wider range of commands.

Initial reviews found that IE8 also loaded web pages significantly faster than its predecessor, IE7, and that it matched Firefox for speed.

Microsoft is anxious to boost use of its browsers, which have 73 per cent of the browser market compared to Firefox's 19 per cent share.

Prior to the launch of Firefox four years ago, Internet Explorer had over 90 per cent of the market, and Microsoft's fading power on the internet is a chief strategic concern.

Firefox made its biggest gain in June when more than 8 million people downloaded a new version in the first 24 hours of release. (dpa)