The authors would like to thank their friend JD for asking the innocent question that started all of this off. They'd also like to thank the National Assocation of REALTORS, specifically the Center for REALTOR Technology, for giving them the time during the work day to work on this paper. It should go without saying, but we'd also like to thank all the developers who have worked on, and continue to work on, the Open Source software that we love to use everyday.