Internet Explorer 7 Release Candidate 1 contains all the features Microsoft hopes to include in the final product, its first major update for the program in years. Among the bells and whistles is the ability to open multiple "tabs" in the same browser window - a popular function in rival Mozilla's Firefox browser - plus updated security functions.

The near-final release is aimed at industry professionals and tech experts who may help the world's largest software company spot last-minute kinks and bugs.Microsoft won't say how many people have downloaded previous test versions.

Tony Chor, a group program manager with Internet Explorer, said the company also has not decided whether it would put out one more test version before the final product is released. He said Microsoft is currently planning to make the final version of IE7 broadly available in the last three months of this year, barring any unexpected problems.

IE 7 will be available for download for people using Windows XP, and it will be included in the forthcoming version of Windows, called Vista. After many delays, Vista is currently