Michael Sperber is an expert in creating high-level software models for complex problem domains. These models allow developers and users to represent domain-specific knowledge directly in the software, rather than forcing them to use awkward technical models. R. Kent Dybvig is a professor in the computer science department at Indiana University. His primary research interest is programming languages. Matthew Flatt is associate professor in the school of computing at the University of Utah. He works on advanced programming languages, including language design, formal semantics, language implementation, and programming environments. Anton van Straaten is a software developer and consultant with a strong interest in the design and development of programming languages. He developed the award-winning software product Class(y), an object-oriented language extension to the Clipper database language.