Microsoft has announced that Windows 8 will include two versions of Internet Explorer 10, a desktop version and a Metro version, which will be optimized for tablets. The Metro version will offer a plugin-free experience by dropping all support for browser plugins, including Flash.

Metro IE10 will be primarily HTML5, according to Dean Hachamovitch, head of the Internet Explorer team, who made the announcement on Microsoft's blog.

“The experience that plugins provide today is not a good match with Metro style browsing and the modern HTML5 web,” he wrote. “The mobile era is about low power devices, touch interfaces and open web standards – all areas where Flash falls short.”

Hachamovitch explained that today's web is mainly based on HTML5 and is designed for a plugin-free experience. Microsoft recently reviewed 97,000 web sites and found that while 62 percent of them use Flash, many only use it to display ads. Additionally, a number of sites using Flash fall back to HTML5 if a user's browser doesn't support the plugin. Microsoft has not mentioned its own Silverlight plugin for interactive media in relation to the Metro plugin-free experience.

The desktop version of IE10 will continue to support all plugins and extensions. The Metro version will offer all the main navigation keyboard shortcuts and mouse support, including creating tabs, moving between tabs, losing tabs, entering addresses and searching.

“I'm using this browser full-time, and given the amount of time I spend in Windows Phone, the same experience and use of touch is definitely a plus,” wrote Steven Sinofsky, a Windows engineer, on the Microsoft blog. “But you can decide on what works best for you, and not compromise.”

According to Microsoft, the Metro version will improve battery life as well as security, reliability and privacy for consumers. The company believes that while plugins were important early on in the history of the web, they would now detract from the user experience of browsing in the Metro style user interface.

“The reality today is that sites are already rapidly engineering for a plugin-free experience,” wrote Hachamovitch. “Google, for example, recently launched their HTML5 YouTube site for phones. A previous IE blog post discussed how plugin-free sites are becoming more mainstream, and what sites can do to run plugin free.”

He added that consumer sites and “line of business” applications that require legacy ActiveX controls will continue to run in the desktop browser on Windows 8. Users will have the option of selecting “Use Desktop View” in Metro IE to access these sites.