The goal of the Miami-Dade GIS geoJSON project is to help local developers new to building web based maps for Miami-Dade to easily get local shapefiles and use them in their projects. The GIS files available on the county websites have been converted to a geoJSON format which can be used in other modern web developer tools such as CartoDB and others. (To see GeoJSON at work, look at this example of all county libraries, in a geoJSON format directly inside Github.)
The Miami version of this project is inspired from a similar project from Portland: https://github.com/Caged/portland-atlas.
If you have issues displaying map, use the geoJSON Linter to test your data.
Our recent hackpad notes: (Hackpad)[http://projects.codeformiami.org/projects/miami_dade_gis_geojson]