PGF/TikZ are low- and high-level packages that can be used from LaTeX as well as from the original TeX. The packages allow you to program graphics just as you'd

PGF/TikZ are low- and high-level packages that can be used from LaTeX as well as from the original TeX. The packages allow you to program graphics just as you'd program a document, but it gives you finer control over graphical relations between entities. It's better to check out http://www.texample.net/tikz/examples/ http://www.texample.net/tikz/examples/ to get an idea of what's possible.