Imposm is an importer for OpenStreetMap data. It reads XML and PBF files and can import the data into PostgreSQL/PostGIS databases.
Imposm 2 is in maintenance mode and it's unlikely that we will provide any further releases. Please check out Imposm 3.
It is designed to create databases that are optimized for rendering/WMS services.
See http://imposm.org/ for more information.