Computer Algebra Software for constructive Algebraic geometry. Designed for performing computations and reasoning about geometric objects in classical algebraic geometry, in particular affine and projective algebraic geometry over an algebraically closed field of characteristic 0.
http://www.risc.uni-linz.ac.at/software/casa/
By Martin N. Dunstan.
http://www.dcs.st-and.ac.uk/~mnd/documentation/axiom_tutorial/axiom.html
A GPL CAS based on DOE-MACSYMA. A GPL project.
http://maxima.sourceforge.net/
A general purpose easy program for It is built on top of its own programming language designed for symbolic manipulation of math symbols. Includes information on how to use the software.
http://yacas.sourceforge.net/
A tool to visualize real algebraic geometry: plane algebraic curves, algebraic surfaces and hyperplane sections of surfaces.
http://surf.sourceforge.net/
Originally an extension to Axiom, now a separate product. Binaries are available free for non-profit use, with documentation, tips, projects and links.
http://www.aldor.org/
Software for computing Fourier coefficients of Eisenstein series attached to lattices by M. Kuss and J. Bruinier. Binaries for x86-Linux.
http://www.mathi.uni-heidelberg.de/~bruinier/Readme.eis
By Robert H. Lewis and Michael Wester. Presented as a poster to the 1999 ISSAC Conference.
http://www.fordham.edu/lewis/cacomp.html