(Fortune) -- Facebook founder Mark Zuckerberg is known as a precocious visionary, but as a college-age CEO he was as rebellious and irreverent as the next kid. In his forthcoming book The Facebook Effect: the Inside Story of the Company That Is Connecting the World, author David Kirkpatrick gives an unprecedented look at the rambunctious nerds who created a multibillion-dollar media giant. An adapted excerpt is below.
In the first week of his sophomore year at Harvard, Mark Zuckerberg cobbled together an internet software program he called Course Match. The idea was to help students pick classes based on who else was taking them. If a cute girl sat next to you in Topology, you could look up next semester's Differential Geometry course to see if she had enrolled in that as well. Hundreds of students immediately started using it.