This conference was convened "to explicate programming concepts through the development, examination and comparison of various formal models of these concepts" (per the IFIP Working Group 2.2 on Formal Description and Programming Concepts). This collection of 26 papers represents the results of that charge, while the conference itself was characterized by lively discussions and conversations involving all participants, which served to clarify and crystallize critical issues. The editor hopes some of that liveliness will be communicated to the reader.