Author of GRB to OSM migration toolkit
In my spare time I have been studying the GRB dataset and subsequently created a web based toolkit to merge data from GRB (Grootschalig Referentie Bestand) with OpenStreetMaps
PHP Reverse geocoding library
I've created a PHP abstraction library to perform geocoding from all the known engines. See php-georev-class repository. It work(ed) with all major public services but it was designed to work very well with nominatim geocoder. It's a bit aged as it was written before composer became popular.
reverse geocoding library