W3C Recommendation Research Articles

OWL exports from a full thesaurus

Le Web semantique consiste en une serie d'initiatives destinees a rendre les ressources du Web davantage accessibles aux agents logiciels, de facon a ce que ces agents puissent realiser au moins une analyse et un traitement de l'information rudimentaires. L'A. presente ici l'une de ces initiatives, le langage OWL (Web Ontology Language), en relation avec les thesaurus et les taxonomies. En depit de la complexite et de l'ampleur du projet, il y aura un Web semantique et OWL y jouera un role.

XQuery 1.0 is nearing completion

XQuery is a query language designed for querying real and virtual XML documents and collections of these documents. Its development began in the second half of 1999. We provided an early look at XQuery in Dec. 2002 [1]. XQuery 1.0 is now approaching its publication as a W3C Recommendation, and we would like to update you on its progress. We can speak to this area with even more authority than we did last time, as we both became co-chairs of the W3C XML Query Working Group [2] in summer 2004.

Structural properties of XPath fragments

We study structural properties of each of the main sublanguages of navigational XPath (W3c Recommendation) commonly used in practice. First, we characterize the expressive power of these language fragments in terms of both logics and tree patterns. Second, we investigate closure properties, focusing on the ability to perform basic Boolean operations while remaining within the fragment. We give a complete picture of the closure properties of these fragments, treating XPath expressions both as functions of arbitrary nodes in a document tree, and as functions that are applied only at the root of the tree. Finally, we provide sound and complete axiom systems and normal forms for several of these fragments. These results are useful for simplification of XPath expressions and optimization of XML queries.

An early look at XQuery API for Java™ (XQJ)

In Feb. 2004, the period for submitting Last Call Working Draft comments for most parts of the XQuery specification came to a close. While there is still a great deal of work to be done to make XQuery a W3C Recommendation, the documents have become more stable with each public release. In this column we'd like to provide an initial look at the XQuery API for Java™ (XQJ), a project that is taking place within the Java Community Process (JCP).

A formal semantics of SMIL: a web standard to describe multimedia documents

This paper presents a formal semantics of a subset of SMIL2.0: a W3C recommendation to describe interactive multimedia documents on the Web. This work has been used during the design of this standard to improve its consistency. It is also intended to help SMIL developers to understand the specification. Doing so, it will contribute to increase SMIL chances of success in achieving the interoperability goal and, thus, its impact on the new information society.

OpenMath and MathML: semantic markup for mathematics

Unambiguous representation of mathematics is crucial for communications among humans or among computer systems. OpenMath is a standard aimed at supporting a semantically rich interchange of mathematics among varied computational software tools such as computer algebra systems, theorem provers, and tools for visualizing or editing mathematical text. MathML is a W3C Recommendation for the encoding of mathematics 'on the web' which also includes mechanisms for encoding mathematical semantics. We introduce each of these two languages and describe their relationships.

Anticipating SMIL 2.0: the developing cooperative infrastructure for multimedia on the Web

SMIL is the W3C recommendation for bringing synchronized multimedia to the Web. Version 1.0 of SMIL was accepted as a recommendation in June 1998. Work is expected to be soon underway for preparing the next version of SMIL, version 2.0. Issues that will need to be addressed in developing version 2.0 include not just adding new features but also establishing SMIL's relationship with various related existing and developing W3C efforts. In this paper we offer some suggestions for how to address these issues. Potential new constructs with additional features for SMIL 2.0 are presented. Other W3C efforts and their potential relationship with SMIL 2.0 are discussed. To provide a context for discussing these issues, this paper explores various approaches for integrating multimedia information with the World Wide Web. It focuses on the modeling issues on the document level and the consequences of the basic differences between text-oriented Web-pages and networked multimedia presentations.

XML after 1.0: you ain't seen nothin' yet

The prevalence of XML in discussions of the Web and its application to such diverse application domains in the past year (1998-99) have almost eclipsed the fact that the 1.0 specification, approved as a W3C Recommendation in February 1998, is only the first part of the "structured documents" originally envisioned. The specifications for two more parts-hypertext link types and the stylesheet language-are nearing completion, and the W3C chartered new working groups last year (1998) to generate new members of the family.

An introduction to the Synchronized Multimedia Integration Language

The Web, now a multimedia environment, can handle audio, images, text and video. However, creating TV-like multimedia presentations proves difficult. It either requires complex, timer-based programming in a scripting language (such as Javascript) or an authoring tool for multimedia presentations. To allow a broader audience to author multimedia presentations for the Web, the World Wide Web Consortium developed the Synchronized Multimedia Integration Language. SMIL, an easy-to-learn HTML-like language, allows the use of a text editor to write multimedia presentations. SMIL is a W3C recommendation, and several implementations are available. This article explains how to write a multimedia presentation in SMIL.

Nifty technology and nonconformance: the Web in crisis

The near parity between Microsoft's Internet Explorer and Netscape's Navigator is bringing what had been merely a developers' annoyance firmly into the realm of disaster. The problem is a relatively familiar one: nonconformance or incomplete implementation of standards makes building sophisticated Web pages that work across browsers a difficult and expensive job. Because Web developers have to spend extra time and effort working around quirks in different implementations, they almost always have to privilege general functionality over technological enhancements. Just trying to get pages to look the same across browsers by following the Cascading Style Sheet Level 1 (CSS1) standard-a W3C recommendation finished nearly two years ago (1996)-requires intimate knowledge of the peculiarities of each version of each browser on each platform. IE 4 on Windows, for example, supports about 80 percent of CSS1 and about the same amount on Macintosh, but not the same 80 percent. Navigator 4 supports a little less of CSS1 on both Windows and Macintosh, but again not the same subset and not in the same way. And CSS is just the tip of the iceberg.

HTML 4.0: THE BEGINNING OF MATURITY?

The World Wide Web Consortium (W3C) has published public draft proposals for HTML 4.0. While the W3C does stress that at the moment they are only draft proposals, it also expects that after a period of public and Member review, the HTML 4.0 specification will be endorsed as a new W3C Recommendation.