But isn't Google Maps free?

The most frequent comment we hear

The use of Google Maps (as well as many other map suppliers) is indeed free, but not free at the same time. Google has conditions on the usage of its maps. Generally vendor's have to pay to be able to access the API and use the maps that can be found on their websites. Even printing and distributing said maps is not allowed in many cases.

In addition, while Google Maps are available, the underlying spatial data is not. One can only use the maps as they are offered by Google. If you want to display the map in a different style or try your own routing algorithm, you simply can't. OpenStreetMap offers the "raw" spatial data so that everyone may use it as they wish.

Why do you do it?

Geoinformation is rarely available for free these days. If you want to make a sketch on your homepage or directions on a printed sign, the map is usually proprietary and the license for the data can only be purchased (sometimes very expensive).

The same applies to research and teaching. Teachers and researchers often have to rely on proprietary data - or move on legal thin ice.

When you buy a navigation device, you pay a significant price for the supplied digital maps (this is why you need to pay a hefty price for an SD card with maps of Europe or Mexico). Worst of all often the data published can be incomplete or outdated.

OpenStreetMap ended their dependence on proprietary data providers and focuses on the pure creative activity. Through the cooperation of the members the free geo-database is available to everyone worldwide.

How can I report bugs?

The best way is to register with OpenStreetMaps and then you can directly edit the data. An introduction can be found here
If that is too cumbersome, then you can also directly report minor error on the OpenStreetMaps website. Simply click on or a similar icon on the map screen. This adds a marker on the map which you can move by dragging it around. Write your message, then click "Save" and the other mappers will investigate the error.

How can I participate?

Most of the OSM community members participate by mapping; they collect map data with a GPS device and enter it into OpenStreetMap. Also many draw approved aerial photographs and complete the data locally. Help in "small-scale" is very valuable for the project: Are there areas in which you're familiar, mapped correctly or find errors that you could improve upon? Do you know house numbers off by heart?

Programmers are always in demand at OpenStreetMap, there is plenty to do - to the central database, the editors, the software that creates the maps and all sorts of assistance programs.

Do you have any access to data that OpenStreetMap could use? Aerial photographs, old maps, whose copyright has expired, or the GPS tracks of your fleet of courier vehicles? Bring it on, we can surely use it somewhere.
See the Getting Involved wikipage or the "step by step" instructions.

Do I need a GPS?

One of the ways the data is collected is with a GPS, but by no means is it the only way. Even if you do not have a GPS, you can log in and process data that has been collected by other people, check the quality or bring your own knowledge.