Short answers, pulled from the story.
Jon Kleinberg is an American computer scientist born in 1971, currently the Tisch University Professor of Computer Science and Information Science at Cornell University. He is best known for developing the HITS algorithm for web search and for his research on the algorithmic aspects of social networks, including the small-world problem.
HITS is a web search algorithm Kleinberg developed while at IBM's Almaden Research Center. It categorizes web pages as either "hubs" (pages that link to many valuable pages) or "authorities" (pages linked to by many hubs). The algorithm served as a full-scale model for PageRank and uses eigenvector-based methods to identify important pages in a hyperlinked network.
Kleinberg received the Nevanlinna Prize in 2006, awarded by the International Mathematical Union. The prize is given once every four years alongside the Fields Medal and is the premier distinction in computational mathematics.
Kleinberg was among the first researchers to study not just whether short paths exist in social networks, but how people are able to find those paths using only local information. He modeled this using a grid where long-range connections form with a probability that decays as the second power of the distance, identifying the geometric condition that makes decentralized navigation possible.
Kleinberg co-authored Algorithm Design with Eva Tardos, a widely used textbook on computer algorithms. In 2010, Cambridge University Press published his book Networks, Crowds, and Markets: Reasoning About a Highly Connected World.
Kleinberg received a Bachelor of Science in computer science from Cornell University in 1993, then earned his PhD from the Massachusetts Institute of Technology in 1996. He joined Cornell as a professor in 1996 and has remained there since.