Computer Algebra system, descendent of Macsyma.
Maxima is a system for the manipulation of symbolic and
numerical expressions, including differentiation, integration,
Taylor series, Laplace transforms, ordinary differential
equations, systems of linear equations, and vectors, matrices,
and tensors. Maxima produces high precision results by using
exact fractions and arbitrarily long floating point representations,
and can plot functions and data in two and three dimensions.