There has been a bit of buzz the past couple of weeks over the ability of GitHub to render GeoJSON and TopoJSON files automatically using and embedded Leaflet map and MapBoxtechnology. This buzz is quite justified as it presents an easy way to simply publish and visualize vector data sets. In the weeks since the initial announcement, the community has begun exploring the limits of GitHub’s capability. Probably the two biggest limiting factors are individual file size limits and API rate limits. Some, including myself, are exploring strategies for maximizing the ability to store, disseminate, and visualize data within these confines. For the near term, GitHub will probably not be the place to store terabytes of data or act as the CDN for a high-volume mapping application. That is perfectly fine and there is still a great deal of value to be found within GitHub’s current generous constraints.