WHAT with shrinking government funds and growing competition from online for-profit institutions, American colleges and universities are facing hard times, and being forced to rethink what they do. Richard A. DeMillo, director of the Center for 21st Century Universities at Georgia Institute of Technology, discusses the evolution of universities in his new book, “Abelard to Apple: The Fate of American Colleges and Universities.” Drawing on his experience as the first chief technology officer at Hewlett-Packard, director of the National Science Foundation’s computer and computation research division, and dean of Georgia Tech’s College of Computing, Dr. DeMillo offers an engineer’s view of the challenges facing higher education.