Users & feedback

If you are using Leonardo and you are not mentioned here, please send e-mail to or sign the guestbook. We would like to receive comments, suggestions, animated programs, screenshots, and everything related to your experience with Leonardo.

Uses in courses

University of Pittsburg, Department of Information Science and Telecommunications
INFSCI 0015 - Data Structures and Programming Techniques, Fall 2000, CRN 20813

[...] The instructor uses visualization system Leonardo to demonstrate execution of example programs in the classroom. It is a public domain software for Macintosh. Leonardo also doubles as a complete IDE for C. So, if you have Macintosh, you could download Leonardo and use it for all your courseworks. [...]

Fachhochschule Stuttgart, Hochschule für Druck und Medien, Fachbereich Medientechnik
Vorlesung Informatik, 1. und 2. Semester Audiovisuelle Medien, Prof. Uwe Schulz

[...] Für das Üben am eigenen Computer gibt es mehrere C / C++ Compiler als Freeware im Netz: C/C++ Compiler für den Macintosh [Leonardo]

Università di Roma "La Sapienza", Dipartimento di Scienze dell'Informazione
Algoritmi e strutture dati, Prof. Rossella Petreschi

Leonardo is currently being used in courses of Algorithms and Data Structures at the University of Rome "La Sapienza". Students make use of Leonardo both to observe the animations contained in its Program Repository and to realize their own implementations and visualizations. [...]

LIUC - Università Carlo Cattaneo - Varese
Informatica 1 - Corsi di Laurea in Ingegneria dell'Automazione, Elettronica, Informatica, delle Telecomunicazioni,  AA 2001-02, cod. 060012.

[...] Compilatori e ambienti di sviluppo in C: Turbo C, Leonardo (Mac), LCC-Win32 (Windows), GNU-WIN32 (Windows), DJGPP (DOS). [...]

Citations from scientific papers
L.M. Gómez Henríquez, Software Visualization: An Overview, in Visualization of Software, Informatik/Informatique, nr. 2, April 2001 (html page)
A. Yung, On-line Animation for a Programming Language Course, BCSc Honours (CSC1608), Final Report - 2000, School of Computer Science and Software Engineering (CSSE), Faculty of Information Technology at Monash University, in Melbourne, Australia (html page)
C. Grant, Software visualisation in Prolog, Ph.D. dissertation, University of Cambridge Computer Laboratory, 2000 (html page)
A. Schliep and W. Hochstättler, Developing Gato and CATBox with Python: Teaching Graph Algorithms through Visualization and Experimentation, in Proceedings of Multimedia Tools for Communicating Mathematics (MTCM'00), November 2000 (html page)
A.T. Boyd, Educational Fusion: A Distributed Visual Environment for Teaching Algorithms, Master of Engineering Thesis, Massachusetts Institute of Technology, 1999 (html page)
H. Biermann and R. Cole, Comic Strips for Algorithm Visualization, Technical Report TR778, Computer Science Department of New York University, February 1999 (html page)

M. Edvardsson: 3D Case Tool - An Interesting View on Debugging, Master's thesis, Computing Science Department, University of Uppsala, November 1999 (html page)

Comments from users
"I am one of the developers of Apple's MPW and MacsBug while working at Apple from 1985 until 1994. My career has been developing software tools, and this software tool (Leonardo) is fabulous! Every student of programming should use this to see and understand algorithms"

Dan Allen, <>
(from the guestbook)
"This the a very intelligent piece of software. It's a great place for individuals to start at development but more importantly it provides a visual approach to development that is much needed these days"

Tom Keating, <>
(from the guestbook)

"This is the most amazing C environment i have ever seen. the reverse execution is saving me countless times and infinite println's. i am currently using Leonardo for a graph isomorphism algorithm for a class here at UC Berkeley, if it works, Leonardo will be known world-wide"

Jeremy Archuleta, Berkeley, CA, USA, <> (from the guestbook)

"Your program Leonardo is magnificent! A great way to teach programming, and itself a beautifully done program. Thanks!"

Michael Ackerman, <> (from the guestbook)

"Thanks to people who dedicated their time to build this software. It really made my life easier for illustration of algoritms in my University. I'm just waiting for the complete manual so that I can contribute to Leonardo's program repository with good looking animations."

Leonardo Gomes Holanda, Brazil, <> (from the guestbook)

"[...] one of these fine, rare sites which are dedicated to visualizing programming problems [...]"

Klaus D. Witzel (from Yahoo groups: algorithm-forge)

"Hello, I'm intrigued by Leonardo, and hope to have a closer look at it. I'm a Mac admirer and long-term C programmer of embedded software for telecommunications equipment. It appears that you have made a very nice product. Congratulations too on the quality of your web-based documentation."

Robert Doesburg, Lower Hutt, New Zealand, <> (from the guestbook)

"I am an electrical research engineer and found a reference to your free compiler for mac in the code of a free C program for Particle Swarm Optimization written by Maurice Clerc. I usually use java because it's free. Now with Leonardo I have the option to test and develop C programs in my Mac for free. I want to express appreciation to you for making this possible."

Roberto Baitelli, Brazil, <> (from the guestbook)

"Just ported a FFT routine from CW to Leonardo within 3 Minutes. Great! It worked. Thanks for this amazing product."

Hans-Dieter Zucht, Germany, <> (from the guestbook)

"Leonardo is a great IDE! It's perfect for prototyping C programs and experimenting. Thanks for such a great app!"

Mike Friedman, New York, NY, USA, <> (from the guestbook)

Projects from users



Leonardo implementation of the Per Bak - Kim Sneppen toy evolutionary model, as described in the New Scientist, 8 Nov 1997.


February 3, 1999


Jon Kleiser


Full C+Alpha source code, C project, executable file


StuffIt+hqx, ftp, 7 KB
P'tit Bert 0 Description Projet d'une IA éducable par recommandations floues. Les transitions entre états cognitifs ont des probabilités dépendantes du contexte (variable "énergie"). L'espace des états cognitifs est déformé par l'apprentissage.
Version December 12, 1999
Author Maurice Clerc
Content Full C+Alpha source code, documentation
Download Zip, http, 45 KB (see also html page)