Algorithm animation is the process of abstracting the data, operations, and semantics of computer programs, and then creating animated graphical views of those abstractions. We have done extensive research on algorithm animation, primarily centered on the development of the TANGO, XTANGO, and POLKA systems. Additionally, we have developed an environment for building animations of parallel programs, and we are doing empirical studies of how algorithm animations work.

Both the XTANGO and POLKA systems are available via anonymous ftp. XTANGO is the older system and does not receive much support anymore. POLKA is the newer, more powerful and flexible system and still is being improved and added to. POLKA also includes the hot new system, SAMBA, a front-end which is exceptionally simple to learn and use, but is also quite powerful. Both systems run on top of UNIX and X Windows. We also have a version of POLKA which runs on top of Windows. See the links below for more details on acquiring the systems via ftp. (Note from July 2011: We have not been supporting these systems for a long time. You're welcome to try them if you'd like, but we make no guarantees.)

More about POLKA.
More about SAMBA.
More about XTANGO.

In the past, we made extensive use of algorithm animations in our undergraduate Algorithms course. Animations are shown in class and students build their own animations. Jump to web pages for this course (1997).

Hundhausen, Christopher, Douglas, Sarah, and Stasko, John, "A Meta-Study of Algorithm Visualization Effectiveness", Journal of Visual Languages and Computing, Vol. 13, No. 3, June 2002, pp. 259-290.

Kehoe, Colleen, Stasko, John and Taylor, Ashley, "Rethinking the Evaluation of Algorithm Animations as Learning Aids: An Observational Study", International Journal of Human-Computer Studies, Vol. 54, No. 2, February 2001, pp. 265-284.

Byrne, Michael D, Catrambone, Richard and Stasko, John T., "Evaluating Animations as Student Aids in Learning Computer Algorithms," Computers & Education, Vol. 33, No. 4, 1999, pp. 253-278.

Kehoe, Colleen, Stasko, John and Taylor, Ashley " Rethinking the Evaluation of Algorithm Animations as Learning Aids: An Observational Study", Graphics, Visualization, and Usability Center, Georgia Institute of Technology, Atlanta, GA, Technical Report GIT-GVU-99-10, March 1999.

Stasko, John T, "Supporting Student-Built Algorithm Animation as a Pedagogical Tool" (Formal Demonstration), Proceedings of the ACM SIGCHI '97 Conference on Human Factors in Computing Systems -- Extended Abstracts, Atlanta, GA, March 1997, pp. 24-25.

Stasko, John T, "Using Student-Built Algorithm Animations as Learning Aids", Proceedings of the ACM Technical Symposium on Computer Science Education (SIGCSE '97), San Jose, CA, February 1997, pp. 25-29.

Kehoe, Colleen and Stasko, John T., " Using Animations to Learn about Algorithms: An Ethnographic Case Study", Graphics, Visualization, and Usability Center, Georgia Institute of Technology, Atlanta, GA, Technical Report GIT-GVU-96-20, September 1996.

Stasko, John T., " Using Student-Built Algorithm Animations as Learning Aids", Graphics, Visualization, and Usability Center, Georgia Institute of Technology, Atlanta, GA, Technical Report GIT-GVU-96-19, August 1996.

Byrne, Michael D, Catrambone, Richard and Stasko, John T., " Do Algorithm Animations Aid Learning?", Graphics, Visualization, and Usability Center, Georgia Institute of Technology, Atlanta, GA, Technical Report GIT-GVU-96-18, August 1996.

Stasko, John T. and McCrickard, D. Scott, "Real Clock Time Animation Support for Developing Software Visualizations", Australian Computer Journal, Vol. 27, No. 3, November 1995, pp. 118-128.

Stasko, John T. and McCrickard, D. Scott, " Real Clock Time Animation Support for Developing Software Visualizations", Graphics, Visualization, and Usability Center, Georgia Institute of Technology, Atlanta, GA, Technical Report GIT-GVU-95-21, July 1995.

Muthukumarasamy, Jeyakumar and Stasko, John T., " Visualizing Program Executions on Large Data Sets Using Semantic Zooming," Graphics, Visualization, and Usability Center, Georgia Institute of Technology, Atlanta, GA, Technical Report GIT-GVU-95-02, January 1995.

Lawrence, Andrea and Badre, Albert and Stasko, John, "Empirically Evaluating the Use of Animations to Teach Algorithms", Proceedings of the 1994 IEEE Symposium on Visual Languages, St. Louis, MO, October 1994, pp. 48-54.

Mukherjea, Sougata and Stasko, John T., "Toward Visual Debugging: Integrating Algorithm Animation Capabilities within a Source Level Debugger", ACM Transactions on Computer-Human Interaction, Vol. 1, No. 3, September 1994, pp. 215-244.

Lawrence, Andrea and Badre, Albert and Stasko, John, " Empirically Evaluating the Use of Animations to Teach Algorithms", Graphics, Visualization, and Usability Center, Georgia Institute of Technology, Atlanta, GA, Technical Report GIT-GVU-94-07, March 1994.

Mukherjea, Sougata and Stasko, John T. , "Applying Algorithm Animation Techniques for Program Tracing, Debugging, and Understanding", Proceedings of the 15th International Conference on Software Engineering, Baltimore, MD, May 1993, pp. 456-465.

Stasko, John and Badre, Albert and Lewis, Clayton, "Do Algorithm Animations Assist Learning? An Empirical Study and Analysis", Proceedings of the INTERCHI '93 Conference on Human Factors in Computing Systems, Amsterdam, Netherlands, April 1993, pp. 61-66.

Stasko, John T. and Turner, Carlton Reid, "Tidy Animations of Tree Algorithms", Proceedings of the 1992 IEEE Workshop on Visual Languages, Seattle, WA, September 1992, pp. 216-218.

Stasko, John T. and Turner, Carlton Reid, " Tidy Animations of Tree Algorithms", Graphics, Visualization, and Usability Center, Georgia Institute of Technology, Atlanta, GA, Technical Report GIT-GVU-92-11, June 1992.

Stasko, John T., "Animating Algorithms with XTANGO", SIGACT News, Vol. 23, No. 2, Spring 1992, pp. 67-71.

Stasko, John T., "Using Direct Manipulation to Build Algorithm Animations by Demonstration", Proceedings of the ACM SIGCHI '91 Conference on Human Factors in Computing Systems, New Orleans, LA, May 1991, pp. 307-314.

Stasko, John T., "The Path-Transition Paradigm: A Practical Methodology for Adding Animation to Program Interfaces", Journal of Visual Languages and Computing, Vol. 1, No. 3, September 1990, pp. 213-236.

Stasko, John T., "TANGO: A Framework and System for Algorithm Animation", IEEE Computer, Vol. 23, No. 9, September 1990, pp. 27-39.