1 future of the web brian kelly, uk web focus ukoln university of bath bath, ba2 7ay ukoln is...
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Future Of The Web
Brian Kelly, UK Web Focus
UKOLN
University of Bath
Bath, BA2 7AY
http://www.ukoln.ac.uk/UKOLN is funded by the British Library Research and Innovation Centre, the Joint Information Systems Committee of the Higher Education Funding Councils, as well as by project funding from the JISC’s Electronic Libraries Programme and the European Union. UKOLN also receives support from the University of Bath where it is based.
UKOLN is funded by the British Library Research and Innovation Centre, the Joint Information Systems Committee of the Higher Education Funding Councils, as well as by project funding from the JISC’s Electronic Libraries Programme and the European Union. UKOLN also receives support from the University of Bath where it is based.
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Contents
Data Formats• HML 4.0 • CSS 2.0• Dynamic HTML • XML
Transport• HTTP/1.1
Addressing• URLs • URNs • DOIs
Metadata• PICS • RDF
Implications for the Community
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Web Protocols
The web was originally based on 3 protocols:
• Data Format (user interface): HTML
• Transport: HTTP
• Addressing: URLs
Data format Transport
Addressing
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HTML
HTML:• Defines structure• SGML application• Platform and application independent• Simple and therefore easy to create
but:• Netscape / Microsoft browser wars began• HTML extensions appeared• (Proprietary) scripting languages add new
functionality and also complexity• Universal access begins to be lost
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HTML Develops
During 1997 recognition of dangers of HTML wars
Netscape and Microsoft began working with W3C on development of new protocols
HTML 4.0• W3C recommendation• Primarily defines structure• Layout tags for backwards compatibility
CSS 2.0• W3C draft• Used to define appearance
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CSS 1
CSS level 1:• W3C recommendation in December 1996• Partly supported in IE 3.0• Early designs attempts confirmed power of CSS
but highlighted backwards compatibility issues
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CSS 2
CSS level 2:• Provides richer functionality• Addressed backwards compatibility issues
http://www1.shore.net/~straub/wprmultb.htm
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Making HTML Dynamic
DOM: • Document Object Model• W3C activity• Enables client-side scripting languages to
manipulate HTML and CSS elements and their content
• Sometimes referred to as dynamic HTML
But:• Netscape's implementation is non-standard
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DHTML Example - 1
Making documents "collapsible" is very easy:on mouseclick in heading
set visibility and display of body off
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DHTML Example - 2
Dynamic HTML can be used to develop improved user interfaces.
In this example an expanded menu is provided.
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DHTML Example - 3
DHTML can be used to provide interactive systems - e.g. for CBL, simulation
In this example the pieces can be moved.
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Compatibility IssuesCompatibility with old browsers / other browsers can be provided by:• Using safe, backwards
compatible features• Checking for browser
type by client-side scripting language
• Checking for browsertype by server
Alternatively ignore backwards compatibility
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Using DHTML Locally
Can create a variety of dynamic sitemaps
Your website
Your pointers
Remote websites
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Information Landscapes
Developments such as Web Collections will enable metadata for groups of related resources to be defined for:
• Providing enhanced user navigation• Facilitating printing, off-line browsing, ...• Facilitating indexing• etc.
The term Information Landscapes has been coined to refer to changing, configurable views of networked resources
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Information Landscapes
Landscapes can be developed by / for:• Institutions • Groups (e.g. undergrads)• Service providers • ...
Information Landscapes can be used for delivering information based on:
• Institutional needs and interests• End user's technologies / interface preferences
Implications:• Ownership, legal and copyright issues• Change control • Visibility• Maintenance
What demand is there?
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The End for HTML?
HTML 4.0 and CSS 2.0 provide a rich environment for describing document structure and appearance
But:• Standardisation of new elements is slow
• Supporting communities with specific needs (e.g. Maths) will result in large, complex HTML
• Applications have specific needs (e.g. <STUDENT-NUMBER>
• HTML 5, 6, … does not appear to resolve these issues
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XML
XML:• Extensible Markup Language• Can be regarded as a lightweight SGML• Supported by SGML community• Some support in Internet Explorer 4.0• Netscape promising support in future• XML 1.0 became a W3C recommendation
in Feb 1998• See <URL:http://www.w3.org/XML/>
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XML Applications
MML / CMLScientific communities have defined Math and Chemical Markup Languages
CDFChannel Definition Format provides a proposed standard for push technologies
RDFResource Description Framework provides a proposed standard for a metadata architecture
...
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CDF Example
NewsAgent:• an eLib project• evaluating potential
for CDF for pushing information
Software such as FrontPage 98 have CDF wizards
http://newsagent.ukoln.ac.uk/channel/
<CHANNEL HREF="http://newsagent.ukoln.ac.uk/channel/top.cdf"><LASTMOD="1998-03-05T00:39" /><SCHEDULE> <INTERVALTIME DAY="1"/></SCHEDULE ><ITEM HREF="http://newsagent.ukoln.ac.uk/channel/Events.html"><TITLE>Events</TITLE> </ITEM> Typical CDF File
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Transport
HTTP 1.0 Widely used Inefficient Cache unfriendly
HTTP/1.1 Addresses deficiencies in HTTP/1.0 Cache-aware Available now (e.g. latest version of Apache) Supported in ~ 40% of UK HEIs Browser support?
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Addressing
URLs:• Provide addressing for the web• Consider http://www.dec.com/internet/applications/
• Problems:– Company reorganises website– Individual leaves– Company is taken over!
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Solutions (1)
URNs:Uniform Resource Names: make identification of Internet documents possible.
URN identifiers are persistent and unique.
See <URL: http://www.ietf.org/html.charters/urn-charter.html>
PURLs:Persistent URLs: Point to a resolution services rather than the resource itself.
See <URL: http://purl.oclc.org/>
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Solutions (2)DOIs:
• Document Object Identifiers• Costs $1,000 to register
http://hdl.handle.net/10.1016/S1384107697000225
http://hdl.handle.net/10.1016/S1384107697000225
hdl://cnri.dlib/august95-contentshdl://cnri.dlib/august95-contents
DOIs use CNRI's Handles
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Addressing: Conclusions
Conclusions:• No clear technological winner• Performance issues• Is it just for "publishers"• Business model uncertain• Backwards compatibility and "real world
citation" issues• Still need for information providers to give
careful thought to URL naming schemes
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Metadata
Metadata:• The missing architectural component of the Web• Many developments in progress:
– PICS: "this resource contains bad language rated as X" – Dublin Core: the author's name is xxx and his email
address is yyy
– Web Collections: these set of resources are related and should be download together / printed as a single document / …
– Distributed Authoring: the following can update this document
– ...
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RDF
Resource Description Framework (RDF):• Generic infrastructure for metadata• Based on XML• See <URL:http://www.w3.org/RDF/>
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Using The Technologies
How / when are new technologies to be deployed?• Use "safe" features to ensure backwards compatibility• Check for browser functionality at server• Check for browser functionality at client• Deploy on Intranet for access to internal resources /
external resources• Use tools which can regenerate systems when
standards change / develop• Which tools?• Need to avoid the "tyranny of the template"
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Web ArchitectureWeb architecture is:
• Growing in complexity• Maturing,
becoming more robust
Must understand architecture to avoid:
• Escalating costs
• Degradation of service quality / functionality
Data format
Transport
Address-ing
Metadata
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Community Issues
Issues which the community need to address:• Can we agree on a minimum recommended
browser spec?• Can we use more sophisticated technologies to
cater for variety of browser technologies?• How can we share experiences / knowledge of
what we're doing?
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WebWatch
Project based at UKOLN to monitor web developments in UK
Analysed various communities:
• University entry points• eLib projects• Public libraries
Server software
Nos. of hyperlinks
File size (HTML)
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Web Focus ROADS GatewayA ROADS gateway (software used by SOSIG, OMNI, etc. gateways) being developed to support UK HE web teams:
• AUPs• Guidelines• …
Your feedback needed
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Questions?