IWMW 2002: Web standards briefing (session C2)

A centre of expertise in digital information management
Web Standards Briefing
Brian Kelly
UKOLN
University of Bath
Bath, BA2 7AY
Email
B.Kelly@ukoln.ac.uk
URL
http://www.ukoln.ac.uk/
UKOLN is supported by:

2
Contents
• Introduction
• Standards
• The Original Web
Architecture
• Architectural
Developments
• Deployment Issues
• Discussion
Aims of Talk
• To give brief overview
of Web architecture
• To describe
developments to Web
standards
• To briefly address
implementation
models
Aims of Talk
• To give brief overview
of Web architecture
• To describe
developments to Web
standards
• To briefly address
implementation
models
Please feel free to ask questions at any time, especially
to clarify any unexplained TLAs or XTLAs
Please feel free to ask questions at any time, especially
to clarify any unexplained TLAs or XTLAs

3
About Me
Brian Kelly:
• UK Web Focus – a JISC-funded post to advise
HE and FE communities on Web developments
• Based in UKOLN - a national focus of expertise in
digital information management based at the
University of Bath
• Involved in Web since 1993, while working in the
Computing Service at University of Leeds
• Represent JISC on the World Wide Web
Consortium (W3C)

4
Standards in HE/FE Context
Standards are important in the HE and FE
sector to:
• Ensure widespread access to resources
• Enables resources to be reused and repurposed
• Ensure scholarly resources can be preserved
• Address accountability of public funding
• Minimise resource costs for upgrading systems
• Provide universal access to resources (cf
disability legislation)

5
Standards
Need for standards to provide:
• Platform and application independence
• Avoidance of patented technologies
• Flexibility and architectural integrity
• Long-term access to data
Ideally look at standards first, then find applications
which support the standards. However it can be difficult
to achieve this ideal!
Before the Web
Access to resources typically required use of software
vendor’s software – which was only available on limited
no. of platforms. Often the software would be licensed.
The goal of the Web was to provide universal access to
resources. Who could argue with this goal?
Before the Web
Access to resources typically required use of software
vendor’s software – which was only available on limited
no. of platforms. Often the software would be licensed.
The goal of the Web was to provide universal access to
resources. Who could argue with this goal?

6
Standards and the Web
W3C
• Produces W3C
Recommendations
on Web protocols
• Managed approach to
developments
• Protocols initially
developed by
W3C members
• Decisions made by
W3C, informed
by member &
public review
IETF
• Produces Internet
Drafts on Internet protocols
• Bottom-up approach to developments
• Protocols may be 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, PDF)
• May emerge as
standards
PNG
HTML
Z39.50
Java
PNG
HTML
Z39.50
Java
HTML, XML, PNG, …HTML, XML, PNG, …
HTTP
URN
whois++
HTTP
URN
whois++
HTML
extensions
PDF and Java?
HTML
extensions
PDF and Java?

7
The Case For W3C Standards
Why use open standards developed by the
W3C? Why not leave it to the marketplace?
 W3C’s open standards have been developed in
an open environment, with the aim of achieving
platform and application independency
 Commercial companies develop proprietary
formats in order to maximise their profits and
dividends to shareholders
 W3C’s open standards have been developed to
interoperate with each other according to W3C’s
design vision
 Commercial companies typically develop
proprietary formats in isolation, or along the lines
of a company vision

8
Standards, Architectures,
Applications, Resources
This talk touches on several areas
Architectures: models for
implementing systems
Architectures: models for
implementing systems
Standards: concerned with
protocols and file formats
Standards: concerned with
protocols and file formats
Open standards vs. Proprietary
HTML / XML vs. PDF
CSS / XSL vs. HTML
GIF vs PNG
Which standards are applicable
NT / Unix
File system / database application
HTML tools / content management
Apache / IIS
FrontPage / Dreamweaver
Oracle / SQLServer
ColdFusion vs ASP
Development vs. Migration costs
Use of in-house expertise
In-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
Applications: software
products used to implement
systems
Applications: software
products used to implement
systems

9
GIF
As an example of the dangers of use of proprietary
solutions, consider the GIF file format:
• Unisys announce that they hold patent to
compression algorithm used in GIF images and
users of GIF will have to pay
• Following much debate, Unisys require payment
for licence from software developers - and also
for end users of unlicensed software ($5,000!)
• Web community responds with PNG format
• See <http://burnallgifs.org/>
WARNING:
• There is no guarantee that payment will not be
required for proprietary file formats which are
currently free

10
How Does The Web Work?
The Web has three 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.html
3 Remote computer sends file
Welcome to
Netsoft
4 Local computer displays HTML file
Web Browser
Web
server
<HTML>
<TITLE>Welcome</TITLE>..
The <A HREF=“…”>
Netsoft</A> home page

11
Approaches To HTML
Emphasis on managing HTML resources inappropriate:
• HTML is an output format, which cannot easily be
reused (e.g. WAP, e-Books, etc.)
• Need to manage HTML fragments (only partly
achievable with SSIs)
• Need to manage collections of resources
• Need to have single master source of data
• Need to support new developments such as
personalisation
• Difficult to integrate with new formats
Issues
• Should we stop giving HTML courses?
• Should we stop buying HTML authoring tools?
Issues
• Should we stop giving HTML courses?
• Should we stop buying HTML authoring tools?

12
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 latest versions of Web browsers

13
XML Concepts (1)
Well-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
 and are different
XML Namespaces:
Mechanism for ensuring unique XML elements:
<?xml:namespace ns="http://foo.org/
1998-001" prefix="i">
Insert <i:PART>M-471</i:PART>

14
XML Concepts (2)
XML Schemas
• Allow constraints to be applied on XML attributes
• Express shared vocabularies and allow machines
to carry out rules made by people
• Richer than DTDs
• See <http://www.w3.org/XML/Schema>
XSLT
• A language for transforming XML from one DTD
to another, or to another format (e.g. PDF)
• Written in XML
• Knows about XML (e.g. tree structures, etc.)
• See <http://www.xslt.com/>

15
XML Concepts (3)
XLink provides sophisticated
hyperlinking:
• Links that allow you to choose multiple destinations
• Bidirectional links
• Links with special behaviours:
• Expand-in-place / Replace / Create new window
• Link on load / Link on user action
• Link databases
• See <http://www.xml.com/pub/a/2000/09/xlink/>
XPointer
• Provides access to arbitrary portions of XML
resource
• See <http://www.devshed.com/
Server_Side/XML/XPointer/page1.html>
England
France

16
Getting to XML With XHTML
XHTML:
• HTML represented in XML
• Some small changes to HTML:
 Elements in lowercase not 
 Attributes must be quoted <img src="logo" height="50">
 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/>
Note the IWMW 2002 Web site is (mostly) XHTMLNote the IWMW 2002 Web site is (mostly) XHTML

17
CSS
CSS:
• Cascading Style Sheets
• XHTML/XML defines structure, CSS describes
the appearance
• CSS 1.0 and 2.0 now W3C recommendations
• CSS 3.0 in preparation (modularised)
• We should be using CSS:
 Part of architecture
 Ease of maintenance
 Becoming much richer
 Accessibility
• See <http://www.w3c.org/Style/CSS/>

18
SVG
SVG:
• Scalable Vector Graphics
• A language for describing two-dimensional
graphics in XML
• See <http://www.w3.org/Graphics/SVG/
Overview.htm8>
• Also see presentation on XML written in SVG at
<http://www.w3c.org/Talks/2001/12/
IH-Euroweb/W3CInTheWorldslide.svgz>
• WWW 2002 talk at
<http://www.w3c.org/2002/Talks/
www2002-SVG/>

19

20
SVG Example
http://www.karto.ethz.ch/neumann/cartography/vienna/http://www.karto.ethz.ch/neumann/cartography/vienna/

21
SVG and XSLT
This example:
• Originally
written in Java
• Author
realised that
XSLT would
be easier
• Uses SVG for
chess board
and pieces
• Uses XSLT to
move pieces
http://people.w3.org/maxf/ChessGML/http://people.w3.org/maxf/ChessGML/

22
CML, SVG and XSLT
http://www.adobe.com/svg/demos/cml2svg/html/index.htmlhttp://www.adobe.com/svg/demos/cml2svg/html/index.html
A molecule
described in
CML can be
transformed
using XSLT
into SVG,
allowing it to
be displayed
and
manipulated
A molecule
described in
CML can be
transformed
using XSLT
into SVG,
allowing it to
be displayed
and
manipulated

23
SMIL
SMIL:
• Synchronized Multimedia Integration
Language
• A language for authoring of interactive
audiovisual presentations
• Allows you to synchronize text, images,
audio and video in a document
• An XML Application
• See <http://www.w3c.org/AudioVideo/>

24
SMIL Example
http://www.kevlindev.com/tutorials/
basics/animation/svg_smil/index.htm
http://www.kevlindev.com/tutorials/
basics/animation/svg_smil/index.htm
http://www.reseau.it/smil/smilapp_en.htmlhttp://www.reseau.it/smil/smilapp_en.html

25
MathML
MathML:
• An XML
application
for maths
• Various
plugins,
dedicated
readers,
etc.
• Mozilla
renders
natively
See <http://www.mozilla.org/projects/mathml/>See <http://www.mozilla.org/projects/mathml/>

26
Modularisation
How can you:
• Include XML resources such as MathML,
ChemML, etc in XHTML documents?
• Provide a subset of XHTML features in browsers
on devices such as mobile phones, PDAs, etc.?
The answer is:
• XHTML modularisation (modularization )
• See
<http://www.w3.org/TR/xhtml-modularization/>
and
<http://www.xml.com/pub/a/2002/01/16/
xhtml-m12n.html>

27
Addressing (1)
URLs have limitations:
• Lack of long-term persistency
Univ. changes name or department shut down or merged
Directory structure reorganised
• Inability to support multiple versions (mirroring)
URIs:
• Were an address of a resource – and moving a
resource was annoying but not critical
• With the development of “Web services”, structured
resources, B2B communications, etc. the
availability of URIs will be of great importance

28
Addressing (2)
Solutions:
• Unique identifiers possible, but resolution
difficult
• Solutions include DOIs, PURLs,
OpenURLs, etc.
• Interest mostly in publishing sector
• "URIs don’t break - people break them"
• Think about URL persistency & naming
guidelines:
<http://www.ariadne.ac.uk/issue31/
web-focus/>

29
Transport - The Original Roadmap
HTTP/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)

30
Transport - Today
Today:
• Responsibility for development moved from W3C
to IETF
• Little progress with HTTP/NG
• Problems with HTTP/1.1:
Lengthy (176-page) specification without much explicit
rationale for design decisions
Environment has become more complex
Lack of a clean underlying data model
…
• See “Clarifying the Fundamentals of HTTP”
<http://www2002.org/CDROM/refereed/444/>

31
SOAP
SOAP:
• Simple Object Access Protocol
• Facilitates development of machine-to-machine
communications using Web protocols by
providing a richer XML-based messaging
mechanism
• A protocol for invoking methods on servers,
services, components and objects
• Codifies existing practice of using XML and
HTTP as a method invocation mechanism
• See FAQ at <http://www.develop.com/soap/
soapfaq.htm>

32
Metadata
Metadata - the missing architectural component from
the initial implementation
of the web
Metadata - RDF
PICS, TCN,
MCF, DSig,
DC,...
Addressing
URL
Data format
HTML
Transport
HTTP
Metadata Needs:
• Resource discovery
• Content filtering
• Authentication
• Improved navigation
• Multiple format support
• Rights management
Metadata Needs:
• Resource discovery
• Content filtering
• Authentication
• Improved navigation
• Multiple format support
• Rights management

33
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 user
Note that discussions about additional rights
management metadata are currently taking place

34
RDF
RDF (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)
• Applications include:
 cataloging resources  resource discovery
 electronic commerce  intelligent agents
 digital signatures  content rating
 intellectual property rights  privacy
• See <URL: http://www.w3.org/
Talks/1998/0417-WWW7-RDF>

35
RDF Model
RDF:
• Based on a formal
data model (direct
label graphs)
• Syntax for
interchange of data
• Schema model
Resource ValuePropertyType
Property
page.html £0.05Cost
23-Mar-99
ValidUntil
RDF Data Model
page.html £0.05
23-Mar-99
Property
Cost
InstanceOf
ValidUntil
Value
PropObj
Cost
PropName

36
Browser Support for RDF
Mozilla (Netscape's
source code release)
provides support for
RDF.
Mozilla supports site
maps in RDF, as well as
bookmarks and history
lists
See Netscape's or
HotWired home page for
a link to the RDF file.
Trusted
3rd
Party
Metadata
Embedded
Metadata
e.g.
sitemaps
Image from http://purl.oclc.org/net/eric/talks/www7/devday/Image from http://purl.oclc.org/net/eric/talks/www7/devday/

37
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 it too complex?
• Is it the right approach?
But:
• Is it too complex?
• Is it the right approach?

38
RSS – An XML/RDF Application
RSS (Rich / RDF Site
Summary):
• Initially XML, now an
RDF application
• Used for news feeds
• Lightweight
approach that we
should be
investigating (e.g.
see news page on
IWMW 2002 Web
site)
See example of an RSS authoring tool and parser at
<http://rssxpress.ukoln.ac.uk/>
See example of an RSS authoring tool and parser at
<http://rssxpress.ukoln.ac.uk/>

39
Model For News Feeds
Good For User
The end user can
choose her news
feeds, including local
news, news from JISC
services and news from
third parties
Good For Service
The service can chose
its own information
flow model. Its news is
disseminated
automatically.
Good For User
The end user can
choose her news
feeds, including local
news, news from JISC
services and news from
third parties
Good For Service
The service can chose
its own information
flow model. Its news is
disseminated
automatically.
RSS Institution
(e.g. Bath)
RSSCommunity
(e.g. MIDAS)
RSS
External
(e.g. BBC)
Local News
..
JISC News
..
National News
XHTML converted to RSS
Structured database converted to RSS
Zope CMS outputs to RSS & XHTML

40
What About Tomorrow?
Two interesting areas:
The Semantic Web
• Will allow intelligent agents to know about
resources
• AI and ontologists meet the Web
• Uses RDF (Resource Description Framework) –
W3C’s framework for metadata
• Some concerns over scale of problem
• See <http://www.w3.org/2001/sw/>
Web Services
• Highlight of the WWW 10 and WWW 2002
conferences

41
Web Services
The Web:
• Initially used for viewing static resources
• Then interactive services built (e.g. e-learning)
We now want:
• Programmable Web services which can be used
by other Web services using standards Web
protocols
We have experience of the first generation of externally-hosted
Web services (stats services, voting systems, etc.) - see
<http://www.ariadne.ac.uk/issue23/web-focus/>.
The next generation will be programmable and machine-
understandable
Note that concerns over outsourcing may be an issue
We have experience of the first generation of externally-hosted
Web services (stats services, voting systems, etc.) - see
<http://www.ariadne.ac.uk/issue23/web-focus/>.
The next generation will be programmable and machine-
understandable
Note that concerns over outsourcing may be an issue

42
Example
Some examples at
gotdotnet.com:
• Mailsender
• Thumbnail
Generator
Concepts been
around for some time
(see Auditing &
Evaluating Web Sites
workshop)
Now being
standardised (UDDI,
WSDL, SOAP, …) http://www.gotdotnet.com/playground/
services/thumbnailgen.aspx
http://www.gotdotnet.com/playground/
services/thumbnailgen.aspx

43
We’ve Been Here Before
Reusable components available on the network:
• Sounds like COM/DCOM, CORBA, etc. for
reusable program components
Network services for use within a community:
• Sounds like JISCmail, RDN, EDINA, MIMAS,
BIDS, Mirror Service and other JISC Services
• It’s outsourcing – but it’s OK!
Web Services And UK HE / FE Communities
Sounds like a great idea:
• We’ve the organisational framework to develop national services
(JISC, etc.)
• We’ve got the network
• We’ve a community which is willing to exploit centrally-provided
services and wants to avoid reinventing the wheel (haven’t we?)
Web Services And UK HE / FE Communities
Sounds like a great idea:
• We’ve the organisational framework to develop national services
(JISC, etc.)
• We’ve got the network
• We’ve a community which is willing to exploit centrally-provided
services and wants to avoid reinventing the wheel (haven’t we?)

44
Currently...
End user
Local content National content International content
Web Web Web Web Web Web
We should be moving away
from providing separate Web
services with their own
interfaces …
We should be moving away
from providing separate Web
services with their own
interfaces …

45
Currently...
End user
Collection Description
(e.g. Agora)
User Profile
(e.g. Headline)
Authentication
(Athens)
Local content National content International content
Web Web Web Web Web Web
… and separate metadata
repositories and access
services (which are
sometimes centralised) …
… and separate metadata
repositories and access
services (which are
sometimes centralised) …
Agora and headline
are eLib Hybrid
libraries

46
Future...
Content
End user
User profile
Collection
description
Authentication
Metadata Services /
Access (Web) Services
Application Services?
Bookmarks
Spell-
checker
.. and move to Web-accessible,
machine-understandable Web
services as well as seamless
access to content
.. and move to Web-accessible,
machine-understandable Web
services as well as seamless
access to content
Brokered access
provide by
institutional portal
(MLE, …)

47
Other W3C Areas
See
• W3C site map at
<http://www.w3c.org/Help/siteindex>
• TimBL’s Web Design Issues at
<http://www.w3c.org/DesignIssues>
• Web Architecture from 50,000 feet at
<http://www.w3.org/DesignIssues/Architecture.html>

48
Architectures
Let us consider the following areas:
• Content Management
• Systems Architecture
• Access (Browser support)

49
Position Today
What should we be doing today?
• Move away from creating new content in HTML
• Move to XHTML as part of the migration
• Deploying XML applications
• Storing structured information in a neutral
database
• Using a CMS to manage our content
• Deploying B2B applications to avoid human
bottleneck (such as RSS)
Note that these are aspirations. We will, of course,
be constrained by existing systems, resource
implications, vested interests, inertia, etc.
Note that these are aspirations. We will, of course,
be constrained by existing systems, resource
implications, vested interests, inertia, etc.

50
The CMS To The Rescue
HTML authoring tools have limitations (as has HTML).
A CMS (Content Management System):
• Allows fragments to be managed
• Allows collections to be managed
• Allows resources to be stored in a neutral format
(backend database)
• Allows resources to be reused
• Often provides access control
• Often provides workflow processes and project
management
Issues
• CMS can be expensive
• CMS can be free but have support implications
• Which one to choose?
Issues
• CMS can be expensive
• CMS can be free but have support implications
• Which one to choose?

51
Content Management
Storing resources in HTML and GIF/JPEG is:
 Easy to do and is a low cost solution
 Makes reuse and management of resources difficult
GIF /
JPEG
XML
TIFF /
….
On-the-fly
or batch
conversion
WML
HTML
User-agent
Negotiation
Content Management System for:
• Management of content (content maintenance, metadata
management, access rights, project management, …)
• Delivery of content (e.g. user-agent negotiation, alternative file
formats [such as WML], etc.))

52
Systems Architecture
Issues for you to consider:
• Operating System:
Should you go for a Unix OS or Windows NT?
If Unix, should you go for Linux?
• Open Source vs Licensed Solution:
Should you go for an open source solution or buy a
licensed application?
• Package vs Do It Yourself:
Should you make use of a pre-packages solution or
develop your own solution based on a toolkit (e.g.
database, scripting language, …)?
There are no global solutions – your choice should be
based on expertise available locally, resourcing issues,
discussions with partners, solutions provider, etc.
There are no global solutions – your choice should be
based on expertise available locally, resourcing issues,
discussions with partners, solutions provider, etc.

53
Browser Issues
Which approach to browser issues should you take?
Web sites should be usable to old browsers as these
are still in use and we aim to maximise access.
Therefore you should deliver HTML 3.2 / 4.0 and
avoid technologies such as JavaScript and CSS.
Web sites should be usable to old browsers as these
are still in use and we aim to maximise access.
Therefore you should deliver HTML 3.2 / 4.0 and
avoid technologies such as JavaScript and CSS.
Old browsers are broken and fail to
implement new technologies which
provide (a) richer functionality (b)
support for new devices and (c)
better support for people with
disabilities.
Therefore you should use the latest
stable versions of HTML (XHTML),
CSS, etc.
Old browsers are broken and fail to
implement new technologies which
provide (a) richer functionality (b)
support for new devices and (c)
better support for people with
disabilities.
Therefore you should use the latest
stable versions of HTML (XHTML),
CSS, etc.
NOTE
• Use of ‘clean’ HTML should
degrade gracefully
• XHTML is a useful transition
• User-agent negotiation may
be relevant
QUESTION
• Should organisations /
community implement a
browser policy?

54
Conclusions
To conclude:
• Standards are important
• HTML won’t do the job
• XHTML is a useful transition
• Many new standards being developed
• Need to keep up-to-date and avoid developing
systems with built-in obsolescence
• We’ll need a CMS to manage richly functional
institutional Web services
• “Web services” should be important – and we
shouldn’t be too concerned about using remote
services

55
Questions
Any questions?

IWMW 2002: Web standards briefing (session C2)

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