OpenFreeMap is an open-source map hosting service that allows users to display custom maps on their websites and apps for free, with no limits on the number of map views or requests. The service uses map data from OpenStreetMap and provides weekly full planet downloads in Btrfs and MBTiles formats. The project aims to be self-sustainable through donations, with the goal of covering server costs. The developer has open-sourced their map tile infrastructure, which can be self-hosted or used through the public instance.