Asymptote is a powerful script-based vector graphics language that
provides a natural coordinate-based framework for technical drawing.
Labels and equations are typeset with LaTeX, for high-quality
PostScript output.

A major advantage of Asymptote over other graphics packages is that
it is a programming language, as opposed to just a graphics program:
it can therefore exploit the best features of script (command-driven)
and graphical user interface (GUI) methods.

WWW: http://asymptote.sourceforge.net/