On June 29, Microsoft made its second preview build of Internet Explorer (IE) 10 available to testers for download.

"IE10 Platform Preview 2, the same HTML5 engine seen in the recent public 'Windows 8; demos, is now available for download," Microsoft officials blogged on the IE Blog today. The new build is available via this link.

The new preview build provides support for SS3 Positioned Floats, HTML5 Drag-drop, File Reader API, Media Query Listeners and initial support for HTML5 Forms, according to the post. There are also general HTML5 application performance improvements, battery-life-efficiency improvements and overall web-application security improvements, the team members said.

Microsoft is building around the "Trident" rendering engine in IE 10 with Windows 8. Windows officials have said that Microsoft will expect developers to use HTML5, JavaScript and CSS to build new immersive applications for Windows 8. Microsoft execs so far have made no statements about how/when/if the company will also support other development technologies in Windows 8.

Microsoft officials have said to expect new test builds of IE 10 every three months. The first IE 10 preview was released in April 2011.