METAPOST is powerful language for creating technical drawings and a program my John Hobby, it is found in most if not all TeX distributions. While most LaTeX compilation assistants do not pay much attention to METAPOST, it is very well integrated in BSD Owl Scripts so that preparing a LaTeX document containing beautiful METAPOST pictures is achieved by a Makefile as simple as
DOCUMENT= galley.tex SRCS+= figures.mp .include "latex.doc.mk"
It is also possible to produce pictures for themselves, using a Makefile similar to
DOCUMENT= figures.mp MPDEVICE= eps pdf png svg .include "mpost.doc.mk"
It will produce EPS, PDF, PNG and SVG versions of the figures.
If you do not know METAPOST here are few figures drawn with it: