GridWorld was the case study for the 2008 - 2013 AP CS exams. GridWorld uses an engaging environment that allows students to create and test actors with a wide variety of behaviors.
Narrative by Chris Nevison and Barbara Cloud Wells, Colgate University
Framework design and implementation by Cay Horstmann, San Jose State University
Images created by Chris Renard, a student at the School for the Talented and Gifted, Dallas Independent School District
Information about GridWorld in the AP course is available from the College Board.
This unofficial site contains additional information for GridWorld enthusiasts.