Only Version 2 CDFs may be accessed with the current CDF distribution. Version 1 CDFs must be converted to Version 2 CDFs using the CDFconvert program in a CDF distribution prior to CDF V2.5 before they will be readable.
All supported CDF operations are available using the Internal Interface. A subset of these operations are available using the Standard Interface. The Obsolete Interface is no longer supported. (Applications written for CDF Version 1 must be ported to the Standard or Internal Interface of CDF Version 2.)