http://tags.library.upenn.edu/tag/GIS+cml PennTags Feed http://tags.library.upenn.edu/makerecord/url/3749 http://tags.library.upenn.edu/makerecord/url/3749 NeighborhoodBase includes maps and data from a number of city agencies, plus census data. All data is available for aggregation at a range of geographic levels (ie, wards, census tracts, etc). A great source for data and maps about life in Philadelphia.