Opencaching-DE
The OpencachingDeutschland project (OCDE)
www.opencaching.de is a major Geocaching website in Germany. The OpencachingDeutschland project contains the website's code, including all third-party libraries needed to run it. It is one of two major Opencaching code forks; the other one being Opencaching-PL. Feel free to use it under the provided license terms for setting up your own open and free Geocaching listing service! The code can easily be translated to other languages.
Opencaching.DE code branch - https://github.com/OpencachingDeutschland/oc-server3
The up-to-date version is deployed to a single server which is connected to four domains (www.opencaching.de, www.opencaching.it, www.opencachingspain.es, www.opencaching.fr); that is, all those sites run on one server with the same code and database. This is currently the only server running up-to-date OCDE code, besides of test and development machines.
Other OC sites branched off the OCDE code (see graph), doing minor (CZ, NL) major (SE/NO) or huge (PL) modifications. Opencaching.NL later switched to OCPL code, and Opencaching.SE/NO was shut down in 2014 after plans for a merger to Opencaching.DE were discarded.
Both the OCDE and OCPL code branches use the same public API (called OKAPI, see http://opencaching.pl/okapi/).
See also Opencaching-PL, Opencaching.de Wiki.