OpenFreeMap is a free service that allows you to display custom maps on your website or apps. You can self-host or use their public instance, all of which is open-source with no ‘open-core’ model. They use map data from OpenStreetMap and offer unlimited map views and requests for free without any registration, user database, API keys, or cookies. The creator, Zsolt Ero, developed this project after years of running his own map tile infrastructure for MapHub. They offer weekly planet downloads and are working towards sustainability through donations. The unique tech stack involves nginx serving a Btrfs image with 300 million hard-linked files. Commercial usage is allowed, and attribution is required.
https://openfreemap.org/