Free Software for Mathematics

There will be an overview of Free Mathematical Software in four categories:

Software for Maths Education in School level.
Software for College level maths e.g. Linear Algebra, Numerical Analysis etc
Software for plotting mathematical functions, graphs etc.
Software useful in research, specially for Abstract Algebra, Algebraic Number Theory etc.

Brief introduction is possible with Dr. Geo, Maxima, Singular, GAP, GNUPLOT etc.

Discussion on topics covered by the software, resources for the software, and also share working experiences with some of software.