OpenStreetMap
OpenStreetMap (OSM) is a collaborative, open-source mapping platform that provides free, editable geographic data of the world. It allows users to collect, contribute, and use map data under an open license, similar to a 'Wikipedia for maps'. Developers can access this data through APIs and tools for applications like navigation, GIS analysis, and location-based services.
Developers should learn OpenStreetMap when building applications that require geographic data, such as mapping services, logistics, urban planning, or real-time tracking, as it offers a free, community-driven alternative to proprietary map providers. It's particularly useful for projects needing customizable, up-to-date map data without licensing fees, and for contributing to open data initiatives.