Although Microsoft has yet to release the final version of IE 7, its rival has posted a Yahoo-optimized version of the Web browser. The browser is essentially the IE 7 browser with a number of tweaks, such as Yahoo home pages, Yahoo as the default search engine and a Yahoo toolbar.

A Microsoft representative declined to comment on the fact that IE 7 is available from Yahoo before it is available from the software giant. Microsoft has touted Yahoo's work as an example of the way other companies can customize the new browser.

The software maker has said it will make IE 7 available in the coming days for download, with automatic updates slated to go to IE 6 users next month. It has launched several publicly available test versions of the new browser.

Microsoft's first major overhaul of the browser in years, IE 7 adds features such as tabbed browsing, built-in RSS reader and improved printing. The company has included a number of security enhancements as well, including an antiphishing filter.