Jmath is a Computer Algebra System (CAS) for high school students. What Jmath can do plot mathematical functions, Solve equations, find intersection, show min/max points, plot tangent, find derivative, and integrate. On Jmath homepage you can find also version for any OS. Version 0.9.2 fixed bug that seen on some computers, can't draw functions except y=x, fixed derivative bugs, fixed log() bug, and fixed inequality.
||Windows 98/Me/NT/2000/XP/2003 Server, Java 1.5