Exploring the OpenStreetMap community

The OpenStreetMap is not just about the data, there is a vibrant community that meets both online and in person all over the world. People meet to do mapping, develop software and even to write this book! 

Mapping parties and other social events

A mapping party is when members of the OpenStreetMap community get together to collect and add information to OpenStreetMap. One way of deciding who maps where is by creating a cake. Below is an example "cake" from a Fleet Street mapping party in London that took place in May 2010.  As you can see, the area is divided up and numbered. Those who are attending pick a section they want to map and go collect data there. There is now a tool which makes this process easier called MapCraft (  Some events bring people together to map on the way to a pub, where they gather socially afterwards. On other occasions, both the data collection and mapping occur, with a central meeting point such as a library, office or coffeeshop. 


People come together in this way for a weekend or in the evenings, to map a specific area or simply catch up with other local contributors. There are also code sprints when OpenStreetMap contributors get together to improve OpenStreetMap software applications.

At many of these types of events it is common to create an actual map cake. The tradition of the map cake comes from an idea introduced by Iván Sánchez Ortega from the Spanish OpenStreetMap community. The idea is that if your data license is truly open, then it is perfectly reasonable to take the geographic data, print it on a cake and then consume that cake, without breaking any licensing rules. This has lead to many cakes being made for social events all over the world! Below is a map cake from a mapping party held at the World Bank in Washington D.C.


Mailing lists

The OpenStreetMap community has many mailing lists. There are lists for specific interests or topics, specific countries or regions, as well as general lists for discussion and for new people to ask questions. To find a current list of mailing lists, refer to


Many people hang out on IRC, in an online chat room. This is used to collaborate and help each other in real time.  This occurs on on the server The most popular channel is #osm, but for more complex development questions, the #osm-dev channel is better. Often each language or region will often have their own channels. There is a full list of channels that people from the community use available on the wiki:

You can use special software to access an IRC chatroom, but it is also possible to do it through your web browser.  To access IRC through your web browser go to Once you are there, choose a nickname and select the channel you would like to join.


There is a question and answer site available in a similar style to StackOverflow. This is where people can ask and answer questions and vote on the usefulness of an answer.


There are additionally web forums for discussing OpenStreetMap available at These are less active than the mailing lists for many topics, but some communities prefer to use them for discussion instead of the mailing lists.

State of the Map conference

There is an annual conference called State of the Map or SotM, where people interested in OpenStreetMap from all over the world come together to discuss topics related to OpenStreetMap. The past few years have included one business day and two community days. The business day is for commercial interests surrounding OpenStreetMap and the community days are inclusive of any topics related to OpenStreetMap. State of the Map has its own website which includes general conference information (