Common Data Format (CDF) is a conceptual data abstraction for storing multi-dimensional data sets. The basic component of CDF is a software programming interface that is a device independent view of the CDF data model. The application developer is insulated from the actual physical file format for reasons of conceptual simplicity, device independence, and future expandability. CDF files created on any given platform can be transported to any other platform on to which CDF is ported and used with any CDF tools or layered applications. A more detailed introduction to CDF can be found in the CDF User's Guide. A comparison between CDF, netCDF, HDF and HDF5 is available at http://cdf.gsfc.nasa.gov/html/FAQ.html.