
The Platform Preview of Internet Explorer 9 will run only in Windows 7, Windows Vista Service Pack 2 (SP2) and Windows Server R2. That update was notable for adding other Windows 7 features to Vista last year.
Internet Explorer has received a fair amount of criticism in the past. With IE9, however, Microsoft is heavilys improveing their new web technologies.
The IE9 Preview provides improved HTML5 support, CSS 3 support (CSS is a technology that makes it easier for designers to specify how they want their sites to look – Colors etc.), and an upgraded JavaScript Engine for better performance of web apps.