OSM, the OpenStreetMap project, is the world's best free and open source of geographic data, maintained and improved by thousands of contributors worldwide. This site brings together resources to help you develop applications using this great data, tools for contributing to the project and infrastrucure components which keep it running.
Learn about the essentials of how geographic data are structured in OSM, how to interact with the OSM APIs, how data flow through the OSM infrastructure and ecosystem. If you want to get an idea of how OSM is structured at a very large scale, then this is a great place to start.
Browse projects related to OSM and get involved with the community helping to make the software better. There are many OSM related projects with different functions, in different programming languages and of different sizes. We'll try to help you find one which interests you.
Browse the developer documentation for projects related to OSM. We try to collect and collate the documentation from many projects to help you find the information you're looking for.