DistrictBuilder is an open source web application for drawing city council and state legislative boundaries in an open, transparent and collaborative manner.
GitHub repo: https://github.com/PublicMapping/DistrictBuilder/
DistrictBuilder supports creation and editing of redisticting plans, display of demographics and election results on an interactive maps, integrates with popular mapping systems, and automatically calculates contiguity, compactness and population statistics for each plan. The software also supports public competitions with customizable scoring metrics and leaderboards. The software is based on Django, Python, GeoServer, OpenLayers and PostGIS.