NLExtract, see www.nlextract.nl, is a project that aims to make Dutch open geo datasets more accessible. Many Dutch nation-wide geo-datasets like BAG (Addresses and Buildings) and Top10NL (Vector Topography) are freely downloadable (e.g. via pdok.nl) but their (XML/GML-) format is not directly usable within applications. A conversion ("ETL") to e.g. Postgres/PostGIS is not trivial because of the data complexity (GML) and size (GBs). NLExtract aims to provide software tools and recipes to unlock these datasets. This is a very high-level introduction to NLExtract, given at the GeoFreedomDay (www.geofreedomday.nl) in Amersfoort on december 15, 2012.
See also https://github.com/justb4/setl for some upcoming ETL tooling we plan to use.