Collection of geographical data as TopoJSON of Berlin.
Unsimplified topojson file, converted from http://daten.berlin.de/datensaetze/ortsteil-geometrien-berlin. File contains the id and name of every district (96).
Converted with the following command lines:
ogr2ogr -f 'ESRI Shapefile' berlin-ortsteile.shp berlin-ortsteile.kml
topojson -o berlin.ortsteile.topojson -p Name --id-property data_id --shapefile-encoding utf8 -- berlin-ortsteile.shp