Microsoft yesterday released the first major test version of its recently named Windows Vista operating system (OS), formerly code-named Longhorn, giving a small number of programmers and tech-heads the opportunity to test the long-awaited successor to Windows XP, which launched in October 2001, reports the AP.

Windows Vista includes user account protection so that users are granted only the privileges required to do their work - a similar to Apple's Mac OS X and the Linux OS. It also ships with Internet Explorer 7, an update that will include protection from viruses and phishing websites.

The IE 7 test version includes support for tabbed browsing, much touted by users of Firefox, Opera, and Safari, writes Internet News. A search box integrated into the browser toolbar offers a choice between MSN and Ask Jeeves, Google, and Yahoo. The browser includes integrated support for RSS feeds.

The product also offers new searching and organizing abilities and a redesigned start menu, writes ZDNet. Other features, such as improved management for laptops and better photo and video handling are expected in later test releases.

Eventually, Vista's features will include better ways to visualize data, such as seeing through windows that are stacked atop each other, more natural file organization and faster searching.

The next beta of Windows Vista is scheduled to be released later this year to a wider audience of about half a million people.