The September 2010 issue of Illinois Alumni magazine, the official publication of the University of Illinois Alumni Assocation, has an article about the history of PLATO entitled In The Time Of PLATO: How Students at Illinois Created Today's Computer Technology 50 Years Ago by Mary Timmins.
Mentioned in the article are Dan Alpert, Don Bitzer, Roger Johnson, Ray Ozzie, C.K. Gunsalus, Lippold Haken, and Paul Tenczar.