The Latest Web Developments

Brian Kelly

UK Web FocusUKOLN

University of Bath

Bath, BA2 7AY

UKOLN is supported by:

EmailB.Kelly@ukoln.ac.ukURLhttp://www.ukoln.ac.uk/

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About Me

Brian Kelly:• UK Web Focus – a JISC-funded post to advise HE

and FE communities on Web developments• Based in UKOLN (UK Office for Library and

Information networking) – a small applied research organisation in University of Bath

• Involved in Web since 1993, while working in Computing Service at University of Leeds

• Close links with Computing Service and Library communities

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About You

What is your involvement with the Web?

What topics would you like covered today?

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Possible Interests

Interests

XML

Hyperlinking

Technologies

File formats

What’s happening to HTML?

Web Architectures

When is it going to stabilise?

Content Management Systems

RDF

Legal issues

Web applications

Web browsers

Netscape or Microsoft?Web Standards

Web Applications

Web Services

Open source vs licensed apps

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Contents

• Standards and the Web• The Original Web Architecture• The Problems• Architectural Developments• Metadata• New Developments• Deployment Issues• Discussion

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Standards, Architectures, Applications, Resources

This talk touches on several areas

Architectures: models for implementing systemsArchitectures: models for implementing systems

Applications: software products used to implement systems

Applications: software products used to implement systems

Standards: concerned with protocols and file formatsStandards: concerned with protocols and file formats

Open standards vs. Proprietary HTML / XML vs. PDFCSS / XSL vs. HTML

Which standards are applicableNT / UnixFile system / database applicationHTML tools / content management

Apache / IISFrontPage / DreamweaverOracle / SQLServerColdFusion vs ASP

Development vs. Migration costsUse of in-house expertiseIn-house vs. out-sourced Licensed vs. open source

Resources: financial and staff costs needed to implement systems

Resources: financial and staff costs needed to implement systems

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Standards

Need for standards to provide:• Platform independence• Application independence• Avoidance of patented technologies • Flexibility ("evolvability" - Tim Berners-Lee)• Architectural integrity• Long-term access to data

Ideally look at standards first, then find applications which support the standards

Difficult to achieve this ideal!

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Deployment Issues

What part of the spectrum are you closest to?

Must support standards Go with the marketplace

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I Support Standards

But:• You probably use PowerPoint, don't you?• Software vendors will subtly suck you into use of

proprietary features• Home-grown solutions can be expensive (where are

all the good Perl / C programmers willing to work on short-term contracts for a pittance in Universities?)

• Standards may not take off – remember Coloured Book network protocols?

• Proprietary solutions may become standardised• Standards may not yet be available (or finalised)• Do users want standards? Will "We support

standards" conflict with "Our services are based on user requirements"?

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I Follow The Marketplace

Good New Labour philosophy, but:• Can you trust your software vendor?• Will your software vendor be around in a few

years time ("I only buy Rover")• Will your system be interoperable? • What happens when you want to interwork

with partners or your organisation merges / is taken over?

• What happens when you want to extend your system beyond the limits set by your software vendor?

IBM was the market leader in the 1970s, but lost out in the PC revolutionWhat will happen if Microsoft is split in two?

IBM was the market leader in the 1970s, but lost out in the PC revolutionWhat will happen if Microsoft is split in two?

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Some Difficulties

We should acknowledge some difficulties in a standards-based approach:

• Keeping up-to-date (look at nos. of documents at http://www.w3c.org/TR/ and size of http://www.diffuse.org/standards.html)

• Spotting the winning standards• Implementing the standard in a timely way• Dealing with the problems of the software vendor• Resources!

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Standardisation

W3C• Produces W3C

Recommendations on Web protocols

• Managed approach to developments

• Protocols initially developed by W3C members

• Decisions made by W3C, influenced by member and public review

IETF• Produces Internet

Drafts on Internet protocols• Bottom-up approach to developments• Protocols developed by

interested individuals• "Rough consensus and working

code"

ISO• Produces ISO

Standards• Can be slow moving

and bureaucratic• Produce robust

standards

Proprietary• De facto standards• Often initially appealing

(cf PowerPoint)• May emerge as

standards

PNGHTMLZ39.50Java?

PNGHTMLZ39.50Java?

PNGHTMLHTTP

PNGHTMLHTTP

HTTPURNwhois++

HTTPURNwhois++

HTML extensionsPDF and Java?

HTML extensionsPDF and Java?

Other• Standards bodies

such as ECMA• Community groups

which can agree on, say, profiles

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World Wide Web Consortium

Much of the development of Web standards is being coordinated by the W3C:

W3C (World Wide Web Consortium):• International consortium, with headquarters

at MIT, INRIA and Keio University (Japan)• Coordinates development of web protocols• Four domains:

• Architecture • Technology & Society

• User Interface • Web Accessibility

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The Web Vision

Tim Berners-Lee's vision for the Web:• Automation of information management:

If a decision can be made by machine, it should• All structured data formats should be based on

XML• Migrate HTML to XML• All logical assertions to map onto RDF model• All metadata to use RDF

A useful overview of Tim Berners-Lee's vision for the Web is given in his book Weaving The Web.

A useful overview of Tim Berners-Lee's vision for the Web is given in his book Weaving The Web.

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How Does The Web Work?The Web has 3 fundamental concepts:

• URLs: addresses of resources• HTTP: dialogue between client and server• HTML: format of resources

The Netsoft home page

1 User clicks on link to the address (URL)http://www.netsoft.com/hello.html

2 Browser converts link to HTTP command (METHOD):Connect to computer at www.netsoft.com

GET /hello.html3 Remote computer sends file

<HTML><TITLE>Welcome</TITLE>..<P>Welcome to <B>Netsoft</B>

Welcome toNetsoft

4 Local computer displays HTML file

Web Browser (client)

Web server

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Web Protocols

Web initially based on three simple protocols:

• Data FormatsHTML (HyperText Markup Language) provides the data format for native documents

• AddressingURLs (Uniform Resource Locator) provides an addressing mechanism for web resources

• TransportHTTP (HyperText Transfer Protocol) defines transfer of resources between client and server

Data FormatHTML

AddressingURL

TransportHTTP

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HTML 4.0, CSS 2.0 & DOM 1.0HTML 4.0 used in conjunction with CSS 2.0 (Cascading Style Sheets) and DOM 1.0 provides an architecturally pure, yet functionally rich environment

HTML 4.0• Improved forms• Hooks for stylesheets• Hooks for scripting

languages• Table enhancements• Better printing

CSS 2.0• Support for all HTML

formatting • Positioning of HTML

elements• Multiple media support

CSS Problems• Changes during CSS development• Netscape & IE incompatibilities • Continued use of browsers with

known bugs

CSS Problems• Changes during CSS development• Netscape & IE incompatibilities • Continued use of browsers with

known bugs

DOM 1.0• Document Object Model• Hooks for scripting

languages• Permits changes to

HTML & CSS properties and content

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CSS

CSS:• Cascading Style Sheets• An open standard

developed by W3C• Separates document

structure (defined in HTML/XML) from the appearance

• Makes maintenance of resources much easier

http://www.w3c.org/Style/CSS/http://www.w3c.org/Style/CSS/

<link rel="style" src="sty.css"<h1>Heading</h1><p>…</p>

<link rel="style" src="sty.css"<h1>Heading</h1><p>…</p>

body {background: blue;}h1: {font-family: arial} p: {font-family: times;

text-align: justify}

body {background: blue;}h1: {font-family: arial} p: {font-family: times;

text-align: justify}Imagine 10,000 HTML files .. With 1 CSS file

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LimitationsHTML 4.0 / CSS 2.0 have limitations:

• Difficulties in introducing new elements– Time-consuming standardisation process

(<ABBREV>)– Dictated by browser vendor (<BLINK>,

<MARQUEE>)• Area may be inappropriate for standarisation:

– Covers specialist area (maths, music, ...)– Application-specific (<STUD-NUM>)

• HTML is a display (output) format• HTML's lack of arbitrary structure limits functionality:

– Find all memos copied to John Smith– How many unique tracks on Spice Girls CDs

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XML

XML:• Extensible Markup Language• A lightweight SGML designed for network use• Addresses HTML's lack of evolvability• Arbitrary elements can be defined (<STUDENT-NUMBER>, <PART-NO>, etc)

• Agreement achieved quickly - XML 1.0 became W3C Recommendation in Feb 1998

• Support from industry (SGML vendors, Microsoft, etc.)

• Support in Netscape 6 (?) and IE 5

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XML ConceptsWell-formed XML resources:

Make end-tags explicit: <li>...</li>

Make empty elements explicit: <img ... />

Quote attributes <img src="logo.gif" height="20"

Use consistent upper/lower case

Valid XML resources: Need DTD

XML Namespaces:Mechanism for ensuring unique XML elements:

<?xml:namespace ns="http://foo.org/1998-001" prefix="i">

<p>Insert <i:PART>M-471</i:PART></p>

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More XML Developments

Momentum behind XML is driving additional standardisation developmentsXML Path

A language for addressing parts of an XML document, designed to be used by XSLT and XPointer

XML Schemas (Ii)Defining the nature of XML schemas and their component parts

XSLTA language for transforming XML documents into other XML documents

…

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XHTML

XHTML:• Extensible Hypertext Markup Language• HTML represented in XML• Some small changes to HTML:

– Elements in lowercase (<p> not <P>)– Attributes must be quoted (<img src="logo" height="50">– Elements must be closed (< p >..</ p >)– Empty elements must be closed (<img src="logo" . />)

• Gain benefits from XML• Tools available (e.g. HTML-Kit from http://www.chami.com/html-kit/)

• See <http://www.webreference.com/xml/column6/>, <http://groups.yahoo.com/group/XHTML-L/> and <http://www.ariadne.ac.uk/issue27/web-focus/>

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TransportHTTP/0.9 and HTTP/1.0:

Design flaws and implementation problems

HTTP/1.1: Addresses some of these problems 60% server support Performance benefits! (60% packet traffic reduction) Is acting as fire-fighter Not sufficiently flexible or extensible

HTTP/NG: Radical redesign using object-oriented technologies Undergoing trials Gradual transition (using proxies) Moving slowly

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Addressing

URLs (e.g. http://www.bristol-poly.ac.uk/depts/music/) have limitations:

• Lack of long-term persistency– Organisation changes name– Department shut down or merged– Directory structure reorganised

• Inability to support multiple versions of resources (mirroring)

URNs (Uniform Resource Names):• Proposed as solution• Difficult to implement (no W3C activity in this

area)

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Addressing - SolutionsPURLs (Persistent URLs):

• Provide single level of redirectionDOIs (Digital Object Identifiers):

• Proposed by publishing industry as a solution• Aimed at supporting rights ownership• Business model needed

OpenURLs• Address mirroring issues

Pragmatic Solution:• URLs don't break - people break them• Design URLs to have long life-span

Further information:<URL: http://www.ukoln.ac.uk/metadata/resources/urn/><URL: http://www.w3.org/Provider/Style/URI>

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Metadata

Metadata - the missing architectural component from the initial implementation of the Web

Metadata -RDF

PICS, TCN,

MCF, DSig,

DC,...Addressing

URL

Data formatHTML

TransportHTTP

Metadata Needs:• Resource discovery• Content filtering• Authentication• Improved navigation• Multiple format support• New devices• Rights management

Metadata Needs:• Resource discovery• Content filtering• Authentication• Improved navigation• Multiple format support• New devices• Rights management

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Metadata Examples

DSig (Digital Signatures initiative):• Key component for providing trust on the web• DSig 2.0 will be based on RDF and will support

signed assertion:– This page is from the University of Bath– This page is a legally-binding list of courses

provided by the University

P3P (Platform for Privacy Preferences):• Developing methods for exchanging Privacy

Practices of Web sites and userNote that discussions about additional rights management metadata are currently taking place

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RDFRDF (Resource Description Framework):

• Highlight of WWW 7 conference• Provides a metadata framework ("machine

understandable metadata for the web")• Based on ideas from content rating (PICS), resource

discovery (Dublin Core) and site mapping (MCF)• Based on a formal data model (direct label graphs)• Applications include:

– cataloging resources – resource discovery– electronic commerce – intelligent agents– intellectual property rights – privacy

• See <URL: http://www.w3.org/Talks/1998/0417-WWW7-RDF>

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RSS – An RDF ApplicationRSS (Rich Site Summary):

• Now an RDF application

• Used for news feeds• Of interest to JISC

(DNER architecture)• Lightweight

approach that we should be investigating

See example of an RSS authoring tool and parser at <http://rssxpress.ukoln.ac.uk/>. Note this service uses CGI – a JavaScript solution is also being developed.

See example of an RSS authoring tool and parser at <http://rssxpress.ukoln.ac.uk/>. Note this service uses CGI – a JavaScript solution is also being developed.

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RDF Conclusion RDF is a general-purpose framework

RDF provides structured, machine-understandable metadata for the Web

Metadata vocabularies can be developed without central coordination

RDF Schemas describe the meaning of each property name

Signed RDF is the basis for trust

But:• Is RDF too complex?• Will it gain acceptance in the market place?

The jury is till out

But:• Is RDF too complex?• Will it gain acceptance in the market place?

The jury is till out

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Other Web Developments

Many Web standards developments are taking place outside W3C:

• UDDI (Universal Description, Discovery, and Integration) – a way of describing Web services in a machine readable way to facilitate location of services by agents. See <http://www.uddi.org/>

• Biztalk – a framework for developing XML schemas for B2B applications. See <http://www.biztalk.org/>

• SOAP (Simple Object Access Protocol) - an XML protocol for exchange of informationSee <http://www.w3.org/TR/SOAP>

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New Web AreasInitially the Web provided:

• An open environment for• sharing information

And aimed to:• provide a rich publishing and collaborative

environment The Web is now:

• Widely used in closed environments (Intranets and Extranets, for ecommerce, etc.)

• Addressing the missing components from the original architecture

• Addressing universally by providing the infrastructure for support of new devices

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E-commerce

E-commerce:• Requires trust• Requires security• Is there a viable business

model?

Developments:• Digital signatures• Public Key Infrastructure• Athens and Sparta in UK

HE

http://www.w3.org/Signature/http://www.w3.org/Signature/

Example 1

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The Mobile Web

The Mobile Web:• Much hype at present• Have you used it?• Is it usable on such a small screen

with slow network times?• What about the resources need to

build a WAP site and a Web site

Example 2

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The Mobile Web CommentsStore resources in neutral format (XML) and generate WAP and WebXML: open storage formatXSLT: Transform XML

XML

WML filefor WAP

XHTML for Web

XSLTengine

XSLTrules

3G promises multimedia and faster networks

Ebook format

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Is It Worth It?

Has the Web stabilised?• Are you thinking about WAP services?• Will you want to (be forced to) make your Web

service accessible?• Will you want to deploy personalised interfaces

(e.g. My.Oxford.ac.uk)• Will your web service move from information

provision to e-business?• Do you want your University web site to use

business-to-business (B2B) protocols to automate transfer of link and news items to HERO?

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What Should I Do?

How can I best exploit new developments?• Storing information in a structured format makes

subsequent redevelopment easier• Be driven initially by standards and architectural

considerations, not by applications• Consider use of more sophisticated web

management tools, rather than HTML authoring tools

• An organisational standards guidelines document (part of a Web Strategy document) may be useful

• Don't work in isolation:– Monitor standards development (e.g. W3C)– Listen to others in your community– Talk and discuss issues within your community

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Authoring

Authoring Web pages:• Was easy• Becoming more difficult as Web becomes more

complex• More difficult to maintain

For large Web sites there is a need for:• More sophisticated tools e.g. content management

systems• Tailoring content for devices?

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Architectural Models There is a need for more intelligent software which can process structured resources or reformat unstructured ones

Intermediaries can provide functionality not available at client:

• DOI support• XML support• Format conversion

Intermediaries can provide functionality not available at client:

• DOI support• XML support• Format conversion

HTML resource

browserWeb server

Web server simply sends file to clientFile contains redundant information (for old browsers) plus client interrogation support

HTML / XML /

databaseresource browser

Server proxy

Client proxy

IntelligentWeb server

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Architectural Models – e.g. XML DeploymentAriadne issue 14 has article on "What Is XML?"Describes how XML support can be provided:

• Natively by new browsers• Back end conversion

of XML - HTML• Client-side conversion

of XML - HTML / CSS• Java rendering of XML

Examples of intermediaries

See http://www.ariadne.ac.uk/issue15/what-is/See http://www.ariadne.ac.uk/issue15/what-is/

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Conclusions

To conclude:• The Web will continue to develop• Standards are important• Proprietary solutions are often tempting because:

– They are available– They are often well-marketed and well-supported– They may become standardised– Solutions based on standards may not be properly

supported by applications

• Metadata is big growth area• Intermediaries may have a role to play in deploying

standards-based solutions• There is a continual need to keep informed

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Questions

Any questions?