Articles tagged as: function.
KAlgebra is a graphing calculator available as FOSS and can be downloaded through Ubuntu Software Center. It can graph in 2D: y = f(x) or in 3D: z = f(x,y). It has excellent features in 2D graphs but have plenty of rooms for improvement in 3D graphs.
GraphCalc is a free and open-source graphing calculator software (FOSS) that is very much useful in producing 2D and 3D function graphs. Even though it was last updated in 2003, it is still very much compatible with operating software as latest as Windows 7. In this article, I discussed the different tips in using it, its limitations and a link to its official website.