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The Latest Web Developments Brian Kelly UK Web Focus UKOLN University of Bath [email protected] http://www.ukoln.ac.uk/ 1 Contents • Introduction • Data Formats HTML, CSS XML • Transport Protocols HTTP • Metadata • Technology and Society • Conclusions 2 UK Web Focus UK Web Focus: • National web coordination post for UK HE community • Based at UKOLN, University of Bath • Responsibilities include: – Technology watch – Information dissemination in variety of ways: – Workshops (national, regional) – Presentations at conferences and seminars – Online – Coordination activities – Representing JISC on W3C • Brian Kelly appointed on 1st November 1996 – Involved with web since January 1993 – Previously worked at University of Newcastle, Leeds, Liverpool, and Loughborough 3 HTML 4.0 HTML 4.0: • Proposal currently under review • Includes: – – – – Advanced Forms: Frame Improvements Table Enhancements Object Support, Script and Style Elements • Addresses accessibility and internationalisation issues • Concerned with document structure - layout addressed by related style sheet proposal • See http://www.w3.org/Press/HTML4 4 CSS CSS1 recommendation agreed in December 1996 CSS 2 draft released in August 1997. Includes: • Font support • Positioning of HTML elements • • Printing Extensions (page breaks, multiple media, etc) • Aural Cascading Style Sheets for visually impaired, in-car use, etc. H1 {pause: 20ms} P.part.romeo { voice-family: romeo, male} P.part.juliet {voice-family: juliet, female} 5 CSS Web services using style sheets are already being developed <html> <Style> .channeltext {font : 32pt verdana; font-weight : bold; text-decoration: none; color : black} .tstext {font : 10pt verdana; font-weight : bold; text-decoration: none; color : black} 6 DOM Document Object Model: • Known as DOM • Platform- and languageneutral interface that will allow programs and scripts to dynamically access content, structure and style of documents • Cf. Dynamic HTML • See http://www.w3.org/ MarkUp/DOM/ 7 Maths MML (Mathematical Markup Language) draft is available: • An XML application • Renderers available (e.g. WebEQ Java application) • See http://www.w3. org/Math/ 8 HTML Limitations Problems with HTML: • Introduction of new tags via standardisation route takes too long • Introduction of new tags by browser vendors is controversial (<BLINK>) and can cause problems with interworking • Many potential tags aren't appropriate for standardisation (<STAFF-NUM>, <HYDROGEN>) These issues are being addressed by XML (eXtensible Markup Language) 9 XML XML: • A meta-langauge • A simple dialect of SGML designed for the Web Design goals: • straightforwardly usable over the Internet • support a wide variety of applications • compatible with SGML • easy to write programs which process XML documents • documents should be human-legible and reasonably clear <?XML VERSION="1.0" RMD="NONE"?> <FAQ> <Q><IMAGE XMLLINK="ques.gif"/>Can I create my own XML documents without a DTD?</Q> <A>Yes. This is an example of a well-formed document, which can be parsed by any XML-compliant parser. However, it won't know how to display it unless you supply a stylesheet.</A> </FAQ> 10 XML Applications XML is already being proposed for a variety of applications: • • MML (Math Markup Language) CML (Chemical Markup Language) • CDF (Channel Definition Format) • MCF (Meta Content Format) • OSD (Open Software Description) • Web Collections • ... 11 HTTP Developments HTTP/1.1 • Addresses problems in HTTP/1.0 – – – – Single resource fetched per request Poor caching model Performance Lack of extensibility • See http://www.ics.uci.edu/pub/ietf/http/ HTTP/NG • Reengineering of protocol architecture • Characterization of the current use of Web • Multiple transports (realtime and multicast, transport level compression, Firewalls, tunneling, and security, ...) 12 PICS PICS: • Platform for Internet Content Selection • Developed in response to US Communications Decency Act (CDA) • Set of standards that facilitate: – Self-rating (content providers can label their content) – Third-party rating (independent labeling services) – Ease-of-use (parents and teachers can use ratings) • See http://www.w3.org/PICS/ Developments: • Following acceptance • Changes in US legislation • Recognition that ratings are a form of metadata 13 PICS/NG and RDF PICS/NG • Proposal for next generation of PICS • Support for string values • For use with digital signatures and assertions (this resource really is from the University of Ambridge, and it is a legally binding description of courses) RDF • • • • Resource Description Framework Based on XML Replacement for PICS/NG Early stages 14 Metadata Requirements Imagine a University prospectus Requirement Protocol Available in Middle East, where PICS (rating system) porn filters in use Resource discovery (find “Bath DubIin Core prospectus”) Legally binding assertions Digital Signature (DSig) Print as single document Web Collections Delivered in appropriate format Transparent Content (HTML, PDF) Negotiation A Metadata Coordination Group has been set up to coordinate these activities 15 Metadata Architecture Metadata - the missing architectural component from the initial implementation of the web Addressing URL Transport Data format HTTP HTML 16 Technology and Society WAI • Web Accessibility Initiative • Aims to make Web formats and protocols more accessible to people with disability • See http://www.w3.org/WAI/ P3 • Platform for Privacy Preferences Project • Enable computer users to be informed about use of their personal data • Proposals include Open Profiling Standard (from Netscape, Firefly & Verisign) and Privacy and Profiling on the Web (from Microsoft) • See http://www.w3.org/P3/Overview.html 17 Conclusions • Web protocols are still being developed • Software vendors seem to be now supporting development of Web standard • Service providers may find chasing new developments expensive • There is a need for a clear understanding of architectural developments 18
