ECCO (http://www.ecco-group.org/) was established in 1998 as part of the World Ocean Circulation Experiment (WOCE) with the goal of combining a general circulation model (GCM) with diverse observations in order to produce a quantitative depiction of the time-evolving global ocean state. The importance of such an endeavor is recognized by numerous national and international organizations, such as the WMO's World Climate Research Programme (WCRP) and UNESCO's Intergovernmental Oceanographic Comission (IOC). These programs have all noted the necessity of synthesizing the diverse remotely-sensed and in-situ observations with known dynamics and thermodynamics through a GCM. ECCO products are in support of the Climate Variability and Predictability (CLIVAR) programme and the Global Ocean Data Assimilation Experiment (GODAE). Major support for ECCO is provided NASA’s Physical Oceanography Program.