These are the leading open source codebases to manage and expose local boundary information. For other apps and services including non-open ones, see the Apps page.
Represent Boundaries (NewsApps Boundary Service)
GeoDjango & PostGIS
The Chicago Boundary Service is a project created of the News Applications team at the Chicago Tribune. See also the Represent Boundaries and Represent Canada codebases that power Represent from OpenNorth which is based off of the original NewsApps Boundary Services codebase.
Public Mapping District Builder
GeoDjango, GeoServer, PostGIS (There’s also an EC2 AMI)
The Public Mapping Project is developing District Builder, an open source software redistricting application designed to give the public transparent, accessible, and easy-to-use on-line mapping tools.
GeoDjango, GeoServer, PostGIS
While not focused specifically on boundaries, it’s also worth noting GeoNode in this list since it’s also based on GeoServer and GeoDjango. It’s a fully featured mapping
platform, so it does a lot more than just boundaries.
Ruby on Rails, PostGIS
While not focused specifically on boundaries, it’s also worth noting CartoDB in this list since it’s also provides many of the needed capabilities. It’s a fully featured mapping
platform, so it does a lot more than just boundaries. Also available as a hosted service – cartodb.com
Searchable Map Template
While also not focused specifically on boundaries, it’s also worth noting something like this Searchable Map Template since it provides a barebones and lightweight way to work with geospatial boundaries. Obviously this isn’t nearly as robust as anything else listed here, but it seemed worth listing here since it’s so simple. Here’s an example for looking up police precincts in Oakland.