1 Comparison with World Wide Web

We compare the MMDD distributed media system with World Wide Web, Portfolio, Hyper-G as well as the standards SGML, Hy-Time, PREMO. We also discuss MMDD's relation to the emerging class of scripting environments designed for highly interactive media-rich environments such as ScriptX. In this note, we assume that the reader is familiar with the design principles underlying the MMDD. (See 9].) 1 1 Comparison with World Wide Web and NCSA Mosaic While we have exported some of our corpora also via World Wide Web 2], 1], WWW and NCSA's design signiicantly diiers from the MMDD's (see section 4), and do not serve the MMDD's spectrum of media and interactivity. We brieey contrast the two designs to more clearly situate the MMDD: 1 Display Metaphor: NCSA Mosaic, and HTML, are based on a word-processor document model: text with inlined media "raisins," which is too rigid for the sort of interactions the MMDD is designed to support, such as staged video sprites and dynamically deened compound objects like "classroom activity" or "historical actor." The MMDD supports a world of co-equal media entities, which may be anything ranging from QuickTime movies, Hypercard stacks or Mathematica programs to streams of music or video. Purpose: WWW and Portfolio were designed to deliver word-processor-like documents, while MMDD is a toolkit designed to provide structures to inform and enrich models or simulations of social systems, which is a much more live, dynamic set of applications. Imagine trying implement SimCity using MS Word. WWW's hypertext model is the same as MS Word, where the documents happen to span whole continents; this is merely a diierence in degree, not in quality. It would be just as ineecient to try to implement a simulation in WWW. Database Services: Mosaic and WWW have no native design for mediating database services. CGI's represent a relatively limited stopgap measure via static data forms which do not streamline the real work of cross-database communication, query-generation, model management, all of which are uniformly and dynamically handled by the NS dbkit's object-oriented methods. The MMDD provides an uniform program-matic interface so that all clients may invoke a single language for 1 While we focus most of our comparison at the level of the user interfaces, it is important of course, to distinguish the underlying World Wide Web architecture from the interfaces that happen to be written for it. 2 multimedia search, annotation and other database functions …