“The world has over a trillion hours a year of free time to commit to shared projects,” says professor Clay Shirky. But what motivates dozens, thousands, even millions of people to come together on the Internet and commit their time to a project for free?  What is the key to making a successful collaboration work? In this hour, TED speakers unravel ideas behind the mystery of mass collaborations that build a better world. Wikipedia founder Jimmy Wales explains what drives people everywhere to contribute to the self-organizing online encyclopedia. Computer programmer Luis von Ahn builds systems that combine humans and computers to help digitize books and translate the web. Social media guru Clay Shirky says when we contribute to the web, we’re building a better world. Software entrepreneur Jason Fried thinks collaboration is key to productivity, as long as we do away with meetings. And coder Jennifer Pahlka believes the government be run like the Internet: permissionless and open.