OpenStreetMap has been making the news quite a bit since last fall. Do you know everything you need to know about this important data project?

1) Definition: OpenStreetMap

Per the OpenStreetMap (OSM) website: "OpenStreetMap is a free worldwide map, created by people like you."

OSM is a database product. There are, however, a number of open source software projects and proprietary products built specifically to edit the database. They are built on the OSM API.

There are also open source projects and proprietary products that allow viewing and routing on maps created with the data.

2) OSM’s Name is Singular

The name of the project is OpenStreetMap; the single word refers to a single database covering the entire world. It’s sometimes erroneously referred to as Open Street Map or OpenStreetMaps.

3) The OpenStreetMap Foundation Manages and Supports the Effort

The Foundation (OSMF) supports, but does not control or direct, OSM. OSMF is an international not-for-profit "dedicated to encouraging the growth, development and distribution of free geospatial data and to providing geospatial data for anyone to use and share."

4) OSM is Changing its License from Creative Commons to ODbL

The old and new licenses enable similar use and sharing of the map data. They both require users to attribute the dataset’s source. The new license, the Open Database License (ODbL), is specifically written for databases and requires enhancements to the data to be made available under the same license. The old license, Creative Commons By Attribution-ShareAlike, required both the data and their rendering, the “artistry,” to both be shared under the original license.

In particular, the new license:

...offers our project more protection. Attribution is more practical. It is a lot clearer on when ‘Share Alike’ is triggered. It also allows you to make maps with layers from different data with incompatible licenses. In short, we want even more people to use our data.

Note that neither of these data licenses (old or new) require editors of the data to provide enhancements back to OSM. That is sometimes required under software licenses.

The goal date to transition to the new license was April 1, 2012. The whole dataset is expected to be offered under ODbL by mid-April.

5) Mapping Parties are Events to Expand OSM

The map database is enhanced by individuals around the world. Some find it fun and rewarding and consider it a hobby. Others simply want a great map of an area that is important to them. Still other offer help in times of crisis, such as earthquakes and tsunamis.

Enthusiasts sometimes host “mapping parties” to tackle a specific geography or theme. These can be home grown or sponsored by a group. Georgia URISA and Georgia 4-H among others, participated in a Mapathon in Atlanta in 2009, for example. These events also serve to educate more people about OSM and how they can help build it.

6) Google’s Recent Decision to Charge Heavy Users of its Google Maps API is Pushing Developers to OSM

OSM has been in the news quite a bit in early 2012 because of a decision Google made about charging a fee to heavy users of its Google Maps API. Previously, it was free to use. This change and other factors have caused well-known and not-so-well-known organizations to switch their mapping applications to use OSM data. There’s even a special website with details on why and how to switch.

Some of the well-known “switchers” include Foursquare (for its browser-based website), Apple (for the latest iPhoto), and Geocaching.com.

7) Where to Get OSM Tiles

The OSM database is quite large. Developers typically display it via smaller chunks, called tiles. OSM serves tiles, but can’t handle the volume some users need.

Those users have several options to access OSM tiles:

• They can pay companies like MapBox to provide the tiles. That’s what Foursquare does.
• They can use existing free tiles provided by organizations like MapQuest. It offers tiles as part of its MapQuest Open Initiative. That’s what Nestoria does.
• They can host the files on their own local or cloud server. That’s what Apple does.

8) Many Apps Offer OSM Data as an Option

While some organizations choose to use a single basemap for their application, others offer more than one. For example, gmaps pedometer defaults to using Google’s Google Maps API, but has the option to switch to OSM data.

9) Some Countries are Heavier OSM Contributors and Users than Others

OSM started in the United Kingdom in response to very tight restrictions on the use of Crown Copyright data from the Ordnance Survey. The UK is still a heavy contributor to, and user of, OSM. Germany also has a large group of contributors and users.

10) OSM has an Annual Conference, The State of the Map

The OSM community and others interested in free geodata gather once a year at The State of Map Conference. That’s where new ideas and initiatives, uses and updates are presented. This year’s event will be held in Tokyo, Japan, September 6th-8^th, 2012.

Special thanks to Richard Fairhurst for reviewing this article for accuracy.