Design by Numbers is a language created by John Maeda for the purpose teaching artists how to program. It was the predecessor to Processing which was created by his students and is no longer developed. This version was created to allow examples from his book and those floating around to still be used.
The language itself has a simple syntax and grammar with a few basic concepts. All code draws to and reads from a simple 100x100 canvas, called the paper and colors are only in greyscale. Different commands allow you to draw lines, points, branch and create loops. In addition, the language has procedures (which do not return a value) and functions.