SurfCast, based in Portland, Maine, its lawsuit on Tuesday in the U.S. District Court for the District of Maine, and is asking for Microsoft to pay unspecified damages and attorneys' fees.

At issue is U.S. Patent 6,724,403, titled "System and Method for Simultaneous Display of Multiple Information Sources," which SurfCast was awarded in 2004.

SurfCast takes issue with Windows' use of live tiles, which are rectangular or square icons in the Start screen of new Windows versions that provide links to applications, websites, contacts and other elements. SurfCast describes itself on its website as a designer of OS technology. It claims to have developed the live tile technology in the 1990s.

In a statement, Microsoft said it was "confident" it would prove in court that SurfCast's claims are without merit and that Microsoft has created a "unique user experience."

Unlike conventional icons, live tiles display dynamically-changing data about the element it links to, such as the number of unread messages in users' email inboxes and alerts about new notifications from their social networking accounts.