Microsoft Research is working on a Web browser that could protect against several common security holes and make it harder for hackers to steal data from PCs.

Gazelle, as the project is known, combines the qualities of a browser with the qualities of an operating system, offering protection to browsers from malicious or unstable code delivered by plug-ins, ads, and other content whose origin may be unknown.

Browsers have evolved over the years from flat data sheets into complex applications that simultaneously display content from all over the Web. Although they're widely used for online banking, shopping, and other activities that can expose personal and financial data to thieves, they don't offer the same protections to users as desktop applications.

"Everyone accepts that applications need to run on operating systems. Yet browsers have never been constructed to be operating systems," Microsoft Research senior researcher Helen J. Wang said on the Microsoft Research Web site.

Instead, browsers allow code and content from different places to co-exist, so that an ad, for example, could cause a browser to slow, freeze, or crash or provide entry to hackers. Browsers also don't systematically control how they get access to system resources such as Webcams or printers.

Researchers at Microsoft Research, the University of Washington and the University of Illinois at Urbana-Champaign will present a paper on Gazelle next month at the Usenix Security Symposium in Montreal.

Gazelle would function as a layer between the operating system and the browser, Wang said, offering some of the same traffic cop-like functions to the browser that operating systems now offer to desktop applications.

In 2007 a Microsoft project called MashupOS detailed various programming and security problems with Web browsers. Gazelle is still a work in progress -- backward compatibility with current Web applications is not yet solved, according to researches.

Google, Yahoo and Adobe, among others, are also tackling problems with browsers and have their own projects going.

Google, in its most direct assault on Microsoft has announced plans to release its own operating system based on its Chrome browser in 2010.

Attend a virtual event on dealing with dealing with security threats from inside your company. It happens July 15. Find out more and register.