Winplot is a standalone computer plotting utility for the Windows (95/98/ME/2K/XP/Vista) environment. It can be useful in design, including in appropriate technology applications such as parabolas for solar technologies.
It can draw and animate a number of surfaces in a variety of formats.
It is available for free from http://web.archive.org/web/20161225084837/http://math.exeter.edu/rparris/winplot.html