SDD is not simply DELTA expressed in xml. We try to deal with many problems the DELTA users and the developer team themselves (see M. J. Dallwitz, T. A. Paine, and E. J. Zurcher (1993 onwards, 1999, 2005) Proposed New Features for the DELTA System)) identified as deficits in DELTA. The SDD proposal is explicitly design to be used as a replacement for the DELTA standard. The following documents here are intended to help DELTA experts in writing software to migrate DELTA applications to SDD conforming applications.