Here’s an implementation of a city generation algorithm (by @tobmansf), inspired by Introversion’s canceled Subversion project and based on the L-system method presented in the 2001 paper Procedural Modeling of Cities: http://tmwhere.com/city_generation.html

The original paper:
https://graphics.ethz.ch/Downloads/Publications/Papers/2001/p_Par01.pdf

One of the authors of the paper went on to create CityEngine, which I’m sure I’ll be talking about more in the future:
http://www.esri.com/software/cityengine