A computational algebra system in Smalltalk (Cuis Smalltalk more precisely).
This is a continuation of some projects started in the MathMorphs group in the University of Buenos Aires in 1997 and 1998.
The goal is to build an extensible and mathematically rigorous environment where one can construct mathematical objects (such as groups, rings, modules, schemes, etc) and operate with them. It currently supports some elementary constructions and computations in group theory, commutative algebra, algebraic geometry and algebraic number theory.
For more details refer to the online documentation in the wiki.