See also DebianScienceMaxima.

Maxima -- Web: http://www.ma.utexas.edu/users/wfs/maxima.html

Description

   A fairly complete computer algebra system, especially for formal calculus.

Presentation in French :

http://logiciels-libres-cndp.ac-versailles.fr/article.php3?id_article=54&var_recherche=maxima