John Mark Ockerbloom (born 1966)[1] is a pioneer in library science. He was the first person to make a substantial effort to catalog online books in a rigorous and comprehensive manner. Formerly at Carnegie Mellon University,[2] from which he earned a PhD in computer science,[3] he is now a "digital library architect and planner at the University of Pennsylvania".[1][2] He is the editor of The Online Books Page, which lists over 35,000 books,[4] all of which are freely available for reading online or by download.