LUIS VON AHN, a computer scientist at Carnegie Mellon University, sold one Internet start-up to Google in 2009, and is now on to another. With the new company, Duolingo, he hopes to tap the... Read more
Over 30,000 still images and video, as well as local information about changing biodiversity, have been uploaded to the Encyclopedia of Life via new tools that let the public contribute as n... Read more