Htrace - Haskell Raytracer (2001) At the end of 2000, I wanted to learn Haskell, a lazy functional programming language. Raytracing is ideally suited to a functional style, so I wrote a raytracer as a way of learning the language. It was written from start to finish in about a day, which is a good indication of a suitable choice of implementation language. I learned haskell from the excellent book