CS

Function parsing

http://warp.povusers.org/FunctionParser/

Perlin noise

http://freespace.virgin.net/hugo.elias/models/m_perlin.htm

http://webstaff.itn.liu.se/~stegu/TNM022-2005/perlinnoiselinks/perlin-noise-math-faq.html

Random number generation

http://paulbourke.net/miscellaneous/random/

http://www.codeproject.com/KB/recipes/SimpleRNG.aspx

http://www.cse.yorku.ca/~oz/marsaglia-rng.html