How the pieces fit together
The Rails port is the Ruby on Rails application that powers openstreetmap.org; it's where OSM's pages and basic API originate. OpenStreetMap's data, "the planet", are stored in PostgreSQL with PostGIS, and rendered into pretty map tiles with Mapnik. The Slippy Map interface for those tiles — what lets you pan and zoom the map — is powered by Leaflet.
There's plenty to know about OpenStreetMap's style of storing & modifying geodata that will help you get how things work. Review the XML schema, Data Primitives, and Downloading data if you want to work on data-related tasks.
Also, OpenStreetMap runs on a relatively small server deployment for its size - see our notes on server hardware for details. There are also API v0.6 mirrors and Dev and Test APIs which help with testing code that interacts with the OSM API.
How to get involved
For larger changes, you may want to get an account on a development server to do serious testing.
The OSM website Rails Port (Ruby)
This does the UI and API for the site. The Rails port page has plenty of useful information for getting started. Design help is needed here: read Rails_port/UI for a quickstart guide for designers. New users can also review pull requests as practice for getting the Rails Port set up. You can also help by contributing translations.
Search, geocoding Nominatim
Desktop map data editor JOSM (Java)
JOSM is one of the most popular and powerful OpenStreetMap editors.
Default style at OSM.org
- 主要文章：Standard tile layer
Other map styles are separate, please see on their wiki pages or look at contact/license footers in a map display.
Online map data editor Potlatch 2 (ActionScript)
Potlatch 2 was the default editor for new OpenStreetMap users. You can also help by contributing translations.
OSM data processing Swiss Army knife Osmium (C++)
Osmium (also known as Libosmium) is a Swiss Army knife for processing OpenStreetMap data. It is a library to read and write OpenStreetMap data and serves as a base for other projects such as Osm2pgsql.
Osmium Tool is a command line programme to convert OSM data between file formats, inspect files, apply updates to files and generate spatial or thematic extracts.
Pyosmium provides the Python bindings of Osmium and offers an easy method to keep a local OSM planet dumps up to date.
OSM data importer for rendering or geocoding osm2pgsql (C++)
Map rendering with Mapnik (C++)
The main backend for the rendering of the maps that are produced from OSM data.