Hi,
Wow, I couldn't even find DOT via google with "dot programming language."
What is it?
It's no programming language but a graph description language...check graphviz.org (I hope Elio is talking about the same DOT that I have in mind ;-) ). There's also a great free mac-only dot file visualizer available at http://www.pixelglow.com/graphviz/ . It's a really useful program.
HTH, Nico