I am a professional, freelance programmer, and have been for some 15 years. I regularly use C++, C, python, php, java, perl, and other languages. SQL systems of every variety, all sorts of other fun database systems. I've designed desktop applications, server software, web pages, p2p systems, etc.
I have experience with automata theory (language design), artificial intellegence (auto assosiative memories, neural networks, etc.), cellular automata, and genetic algorithms.