The World Wide Web has had over 5 years of intensive is a formal specification of the system, and an SGML development, and has expanded from a text-only techni-Declaration, which states the size and shape of various cal documentation system to a multimedia information parameters for processing. A draft DTD (Berners-Lee & base distributed across the planet. Although its tool for Connolly, 1990) and Declaration were in existence, and structural definition, the Hypertext Markup Language were made available for downloading via anonymous FTP (HTML), has been under constant development throughout this period, most browsers have been slow to take at CERN, the European Laboratory for Particle Physics, advantage of all the facilities it offers. At a time when where the Web was invented. there is much debate over the public future of the Web, Unfortunately the draft DTD was accidently deficient it is in danger of partial stagnation. Despite significant in several ways which made it unusable as it stood. The innovations in some areas, the field is still open for software developers who are capable of harvesting the ben-
principal difficulty was that it contained syntactic errors, efits of SGML, the language in which HTML is written. so that it did not parse using any of the standard SGML This analysis of HTML Document Type Descriptions tools, and therefore could not be used by normal SGML (DTDs) reveals where some of the opportunities may lie.