Lots of systems are modular and flexible on the surface, but under the hood, their code is very different, as are the communities surrounding them. Does the structure of the code influence the nature of the development community surrounding that code? I’ll do a case study through code review of four different PHP CMSs: WordPress, Drupal, Tikiwiki, and XOOPS. Then, we’ll look for patterns in their communities. Are there connections, or just coincidences?