The Group on Earth Observations (GEO) has announced a Call for Participation (CFP) in the 5th phase of the Global Earth Observation System of Systems (GEOSS) Architecture Implementation Pilot (AIP-5). The Open Geospatial Consortium (OGC) provides leadership in AIP-5 and invites OGC members and other organizations to respond to the CFP. The CFP document is available at: http://earthobservations.org/geoss_call_aip.shtml.