Below is a list of projects for which we have documentation.
Although the OSM website and API are written in Ruby on Rails, it can be inefficient to run all API calls through it. This software could be looked at as an "accelerator" for the Rails code, giving lower memory usage, more control over database queries and sometimes a faster response.
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.
OSM data is dumped on a regular basis to provide input for many bits of software and services which process, analyse and present geographic data or information derived from OSM. This all starts with a huge file which is produced by this bit of software.