Loader is a tool for preparing geographic data in GML and KML prior to processing with ogr2ogr. Loader provides configuration options for a number of GML datasets such as Ordnance Survey OS MasterMap (Topographic Layer, ITN, OS Highways etc.), Police.UK boundaries etc.
Users configure Loader to use a given GDAL/ OGR .gfs file (which maps the GML elements and attributes to tables/ columns) and an optional preparation routine which pre-processes the data before load (for instance adding classification columns for styling Ordnance Survey OSMM Topographic Layer).
See the project wiki for installation and configuration docs.