Maxima

Maxima combines exact fractions and symbolic algebra with variable-precision numerical work and 2D/3D plots. The core is a terminal program; wxMaxima and XMaxima are included interfaces. Its linked Minimal Maxima tutorial, dated 2005, illustrates a useful distinction: assigning a later radius does not automatically recalculate an expression already stored for a sphere's volume. Explicit re-evaluation substitutes the value, and numer requests a decimal result. The same guide distinguishes := functions that evaluate their body on use from define, which evaluates at definition time. save writes selected expressions or all to a named file and load restores expressions. Keep those expression/session operations separate from a notebook interface's own document controls. Windows, Mac and Linux installations are documented under the GPL project.