Osm2pgsql is one of the work horses of the OpenStreetMap world. It is used to import OSM data into a database which is then used for rendering maps (among other uses). Osm2pgsql is behind the map you see on openstreetmap.org and many others. The program has been around since 2006 and has accumulated many changes and additions over time. And the code has grown more and more complex. Part of that is inevitable because the program does a lot more than when it was started. But part of that is complexity that doesn’t have to be there. For a few months now I have been working on reducing that complexity and want to tell you about that work.