Before Apple’s iPad first burst onto the tablet scene in 2010, a leaked Microsoft concept generated a lot of buzz in the enthusiast community. Called Courier (pictured above), the tablet featured dual displays attached to a folding hinge, along with touch and pen input. However, Microsoft never went forward with the proposal.

More recently,

Source: Hot Hardware – Microsoft Reportedly Developing Folding Surface Tablet Reviving Famed Courier Concept