There are already several implementations of simple raytracers in Clojure on the Web but I couldn't resist implementing one for myself! It is based on the one of the book Ansi Common Lisp by Paul Graham.
Nothing particular, just perhaps the use of protocols for the dispatch of the normal, color and intersect functions and some code for displaying spirals.
Code is available here: GitHub Kototama
A piece of intertube about the Clojure programming language, algorithms and artificial intelligence.