http://www.algoanim.info/Animal2/
Guido Rössling, TU Darmstadt, Darmstadt, Germany
Major work for Animal appears to be around 1999-2000
Publications: Roessling2000, Roessling2002
Animal is a system for developing animations. There are a lot of similarities to Microsoft Powerpoint. Users must download an application (in the form of a Java .jar file) that is the Animal engine. Users then open an Animal .aml file. What users see is something that looks a bit like a slide show, with controls to move through the show either step-by-step, or at an automated pacing.
A large number of animations are available at the project website. Since the results are animations, users cannot interact with the data structures/algorithms.
For instructions on how to install and use Animal, see: http://www.algoanim.info/Animal2/?q=node/290
See also Jhave which supports Animal scripts.