This is a big advance for mapping and open data on GitHub! Last year I was working with Boston and Cambridge to open their mapping data, and in addition to Git

This is a big advance for mapping and open data on GitHub! Last year I was working with Boston and Cambridge to open their mapping data, and in addition to GitHub I was encouraging them to use GeoGit (geogit.org). Some of our projects (bike lanes added each year, buildings changed between 2010 and 2013 datasets & missing on OpenStreetMap, permits added each day) could now be shown in GitHub. I don't think this is the end of GeoGit though... feature-by-feature changes and filtering available in GeoGit are important for 3rd-party databases to keep in sync with an authoritative dataset.