le projet de Simulations interactives PhET à l'Université du Colorado Boulder, crée des simulations mathématiques et de sciences interactives gratuites .
https://phet.colorado.edu/
Copy & paste the above command to any Unix-based system to begin download. Rsync can pick up where it left off and only downloads changes.
It's the most efficient way to stay up-to-date with RACHEL modules.