OpenWiFiMap is a database and map for free network WiFi routers (freifunk and others, too!).
This is a HTML5 map app with data from a OpenWiFiMap database.
Visit the main installation at openwifimap.net or the stripped down version at openwifimap.net/map.html (e.g. for inclusion in other sites via iframe).
Of course, you can easily set up your own map! Here is a (possibly incomplete) list of installations:
If your installation is missing, feel free to add it or tell us by opening an issue.
If you want to submit nodes to the database or if you want to query the database, please take a look at the OpenWiFiMap API documentation.