Next Year`s Web and How To Get There
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Transcript Next Year`s Web and How To Get There
The Latest Web
Developments
Brian Kelly
UK Web Focus
UKOLN
University of Bath
[email protected]
http://www.ukoln.ac.uk/
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Contents
• Introduction
• Data Formats
HTML, CSS
XML
• Transport Protocols
HTTP
• Metadata
• Technology and Society
• Conclusions
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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
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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
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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}
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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}
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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/
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Maths
MML (Mathematical
Markup Language)
draft is available:
• An XML application
• Renderers available
(e.g. WebEQ Java
application)
• See
http://www.w3.
org/Math/
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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)
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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>
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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
• ...
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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, ...)
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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
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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
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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
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Metadata Architecture
Metadata - the missing
architectural component
from the initial
implementation
of the web
Addressing
URL
Transport Data format
HTTP
HTML
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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
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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
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