14 Second Program Visualization Workshop The Algorithm Animation Repository Pierluigi Crescenzi Facolt` a di Scienze Matematiche, Fisiche e Naturali, Universit` a degli Studi di Firenze, Via C. Lombroso 6/17, 50134 Firenze, Italy Nils Faltin Learning Lab Lower Saxony, Expo Plaza 1, 30539 Hannover, Germany Rudolf Fleischer Department of Computer Science, HKUST, Clear Water Bay, Kowloon, Hong Kong rudolf@cs.ust.hk Christopher Hundhausen Information and Computer Sciences Department, University of Hawai’I at Manoa, 1680 East-West Road, POST303D, Honolulu, HI 96822, USA Stefan N¨ aher Fachbereich IV Informatik, Universit¨ at Trier, 54286 Trier, Germany Guido R¨ oßling Department of Electrical Engineering and Computer Science, University of Siegen, H¨ olderlinstr. 3, 57068 Siegen, Germany John Stasko College of Computing/GVU Center, Georgia Institute of Technology, Atlanta, GA 30332-0280, USA Erkki Sutinen Department of Computer Science, University of Joensuu, P.O. Box 111, 80101 Joensuu, Finland 1 Introduction As researchers in theoretical or practical computer science, we are used to publishing our results in form of research papers that appear in conference proceedings or journals. Journals are normally considered more prestigious than conference proceedings because their more rigorous refereeing stan- dards presumably guarantee a higher quality of the published research papers. This well-established practice of publishing research results puts real practical researchers whose main interest is to write software at a certain disadvantage. There is no established way to ‘publish’ software (except for de- scribing the software in a companion paper that may be considered publishable) unless you want to go the long way of commercializing your system. But this usually only makes sense for certain large systems. Therefore, all the effort that goes into the development of smaller programs is usually not rewarded by the academic community because there is no way to make these little programs known in a way that other people can actually use them as they can use published research papers (a research paper is ‘used’ by reading it, a piece of software is ‘used’ by running it). This is in particular the case for programs that visualize or animate algorithms. Often, these animations are written either by instructors who need them for their teaching, or by people developing algorithm animation tools who use them to demonstrate the strengths of their new system. Since writing good animations can be a very difficult task that requires lots of effort and experience, it is a pity that all these nice programs are to a great extent unavailable for the general public (because they will never know about them) and that the authors of the pograms are not rewarded for their efforts. Last year, at the (Dagstuhl Seminar on Software Visualization), this problem was recognized and it was decided to build an Algorithm Animation Repository (AAR). Eight participants of the seminar formed the Editorial Board of the AAR, and the chairman of the Board, Rudolf Fleischer, was given the task to build the repository at his home university HKUST. With additional funding from his