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A centre of expertise in digital information managementwww.ukoln.ac.uk Web Futures Part 1 – Standards Part 2 – Deployment Issues Brian Kelly UKOLN University.

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Presentation on theme: "A centre of expertise in digital information managementwww.ukoln.ac.uk Web Futures Part 1 – Standards Part 2 – Deployment Issues Brian Kelly UKOLN University."— Presentation transcript:

1 A centre of expertise in digital information managementwww.ukoln.ac.uk Web Futures Part 1 – Standards Part 2 – Deployment Issues 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 A centre of expertise in digital information managementwww.ukoln.ac.uk 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

3 A centre of expertise in digital information managementwww.ukoln.ac.uk 3 Standards in an Educational / Research Context Standards are important in an educational and research context 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) Standards

4 A centre of expertise in digital information managementwww.ukoln.ac.uk 4 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? Standards

5 A centre of expertise in digital information managementwww.ukoln.ac.uk 5 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, … HTTP URN whois++ HTTP URN whois++ HTML extensions PDF and Java? HTML extensions PDF and Java? Standards

6 A centre of expertise in digital information managementwww.ukoln.ac.uk 6 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 Standards

7 A centre of expertise in digital information managementwww.ukoln.ac.uk 7 Standards, Architectures, Applications, Resources This talk touches on several areas Architectures: models for implementing systems 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 Applications: software products used to implement systems Standards

8 A centre of expertise in digital information managementwww.ukoln.ac.uk 8 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 WARNING: There is no guarantee that payment will not be required for proprietary file formats which are currently free Standards

9 A centre of expertise in digital information managementwww.ukoln.ac.uk 9 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 1User clicks on link to the address (URL) http://www.netsoft.com/hello.html 2Browser converts link to HTTP command (METHOD): Connect to computer at www.netsoft.com GET /hello.html 3Remote computer sends file Welcome to Netsoft 4Local computer displays HTML file Web Browser Web server Welcome.. The Netsoft home page

10 A centre of expertise in digital information managementwww.ukoln.ac.uk 10 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 training courses? Should we stop buying HTML authoring tools? Issues Should we stop giving HTML training courses? Should we stop buying HTML authoring tools? Data Formats

11 A centre of expertise in digital information managementwww.ukoln.ac.uk 11 XML XML: Extensible Markup Language A lightweight SGML designed for network use Addresses HTML's lack of evolvability Arbitrary elements can be defined (,, 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 Data Formats

12 A centre of expertise in digital information managementwww.ukoln.ac.uk 12 XML Concepts (1) Well-formed XML resources: Make end-tags explicit:... Make empty elements explicit: Quote attributes <img src="logo.gif" height="20" Use consistent upper/lower case and are different XML Namespaces: Mechanism for ensuring unique XML elements : Insert M-471 Data Formats

13 A centre of expertise in digital information managementwww.ukoln.ac.uk 13 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 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 Data Formats

14 A centre of expertise in digital information managementwww.ukoln.ac.uk 14 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 XPointer Provides access to arbitrary portions of XML resource See England France Data Formats

15 A centre of expertise in digital information managementwww.ukoln.ac.uk 15 Getting to XML With XHTML XHTML: HTML represented in XML Some small changes to HTML:  Elements in lowercase not  Attributes must be quoted  Elements must be closed:... ) Gain benefits from XML Tools available (e.g. HTML-Kit from http://www.chami.com/html-kit/ ) See, and Note the IWMW 2002 Web site is (mostly) XHTML Data Formats

16 A centre of expertise in digital information managementwww.ukoln.ac.uk 16 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 Data Formats

17 A centre of expertise in digital information managementwww.ukoln.ac.uk 17 SVG SVG: Scalable Vector Graphics A language for describing two-dimensional graphics in XML See Also see presentation on XML written in SVG at WWW 2002 talk at Data Formats

18 A centre of expertise in digital information managementwww.ukoln.ac.uk 18 Data Formats

19 A centre of expertise in digital information managementwww.ukoln.ac.uk 19 SVG Example http://www.karto.ethz.ch/neumann/cartography/vienna/ Data Formats

20 A centre of expertise in digital information managementwww.ukoln.ac.uk 20 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/ Data Formats

21 A centre of expertise in digital information managementwww.ukoln.ac.uk 21 CML, SVG and XSLT http://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

22 A centre of expertise in digital information managementwww.ukoln.ac.uk 22 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 Data Formats

23 A centre of expertise in digital information managementwww.ukoln.ac.uk 23 SMIL Example http://www.kevlindev.com/tutorials/ basics/animation/svg_smil/index.htm http://www.reseau.it/smil/smilapp_en.html

24 A centre of expertise in digital information managementwww.ukoln.ac.uk 24 MathML MathML: An XML application for maths Various plugins, dedicated readers, etc. Mozilla renders natively See

25 A centre of expertise in digital information managementwww.ukoln.ac.uk 25 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 and Data Formats

26 A centre of expertise in digital information managementwww.ukoln.ac.uk 26 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 Addressing

27 A centre of expertise in digital information managementwww.ukoln.ac.uk 27 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: Addressing

28 A centre of expertise in digital information managementwww.ukoln.ac.uk 28 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) Transport

29 A centre of expertise in digital information managementwww.ukoln.ac.uk 29 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” Transport

30 A centre of expertise in digital information managementwww.ukoln.ac.uk 30 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

31 A centre of expertise in digital information managementwww.ukoln.ac.uk 31 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 Metadata

32 A centre of expertise in digital information managementwww.ukoln.ac.uk 32 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 Metadata

33 A centre of expertise in digital information managementwww.ukoln.ac.uk 33 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 Metadata

34 A centre of expertise in digital information managementwww.ukoln.ac.uk 34 RDF Model RDF: Based on a formal data model (direct label graphs) Syntax for interchange of data Schema model Resource Value PropertyType Property page.html £0.05 Cost 23-Mar-99 ValidUntil RDF Data Model page.html £0.05 23-Mar-99 Property Cost InstanceOf ValidUntil Value PropObj Cost PropName

35 A centre of expertise in digital information managementwww.ukoln.ac.uk 35 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? Metadata

36 A centre of expertise in digital information managementwww.ukoln.ac.uk 36 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

37 A centre of expertise in digital information managementwww.ukoln.ac.uk 37 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) RSS Community (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

38 A centre of expertise in digital information managementwww.ukoln.ac.uk 38 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 Web Services Highlight of the WWW 10 and WWW 2002 conferences Futures

39 A centre of expertise in digital information managementwww.ukoln.ac.uk 39 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. 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. The next generation will be programmable and machine- understandable Note that concerns over outsourcing may be an issue Futures

40 A centre of expertise in digital information managementwww.ukoln.ac.uk 40 Example Some examples at gotdotnet.com : Mailsender Thumbnail Generator Concepts been around for some time Now being standardised (UDDI, WSDL, SOAP, …) http://www.gotdotnet.com/playground/ services/thumbnailgen.aspx

41 A centre of expertise in digital information managementwww.ukoln.ac.uk 41 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?) Futures

42 A centre of expertise in digital information managementwww.ukoln.ac.uk 42 UK HE Example - Currently... End user Local content National content International content Web We should be moving away from providing separate Web services with their own interfaces …

43 A centre of expertise in digital information managementwww.ukoln.ac.uk 43 Currently... End user Collection Description (e.g. Agora) User Profile (e.g. Headline) Authentication (Athens) Local content National contentInternational content Web … and separate metadata repositories and access services (which are sometimes centralised) … Agora and headline are eLib Hybrid libraries

44 A centre of expertise in digital information managementwww.ukoln.ac.uk 44 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 Brokered access provide by institutional portal (MLE, …)

45 A centre of expertise in digital information managementwww.ukoln.ac.uk 45 Other W3C Areas See W3C site map at TimBL’s Web Design Issues at Web Architecture from 50,000 feet at

46 A centre of expertise in digital information managementwww.ukoln.ac.uk 46 Web Futures Part 2 –Deployment Issues

47 A centre of expertise in digital information managementwww.ukoln.ac.uk 47 Architectures Let us consider the following areas: Content Management Systems Architecture Access (Browser support) Deployment

48 A centre of expertise in digital information managementwww.ukoln.ac.uk 48 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. Deployment

49 A centre of expertise in digital information managementwww.ukoln.ac.uk 49 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? Deployment

50 A centre of expertise in digital information managementwww.ukoln.ac.uk 50 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.)) Deployment

51 A centre of expertise in digital information managementwww.ukoln.ac.uk 51 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. Deployment

52 A centre of expertise in digital information managementwww.ukoln.ac.uk 52 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. 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?

53 A centre of expertise in digital information managementwww.ukoln.ac.uk 53 Questions Any questions?

54 A centre of expertise in digital information managementwww.ukoln.ac.uk 54 Questions Any questions?


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