A Reference Implementation is a (from OGC Compliance Testing Program Policies & Procedures 08-134r9)

• fully functional, licensed copy of a tested, branded software that
• has passes the test for an associated conformance class in a version of an Implementation Standard and that
• is free and publicly available for testing via a web service or download.

The Reference Implementation does not need to pass all the conformance classes within the standard. In most of the cases, the Reference Implementation will pass at least the core and possibly some number of extension conformance classes.

Multiple reference implementations can exist for an associated version of an Implementation Standard. The coordinator after reviewing the results and checking the public interface of the software will determine if the implementation can be a reference implementation.

OGC will make its best effort to host Reference Implementations on an OGC server to help others in the community to develop compliant implementations

The following is the list of current reference implementations, their organization and direct links to the services.