Presentations
This talk is an introduction to topic maps that is aimed at the open source community. Topic maps are an ISO standard for interchange of knowledge in the form of subjects (represented by topics), the relationships between them (represented by associations) and other information related to them (represented by occurrences).
Topic maps are machine-processable and the interchange format is defined as an XML vocabulary. The information that they encode can be used for either further machine processing or for presentation to the end-user in some form. Open source components are widely used by topic map processing software. Such component include XML parsers, persistent storage mechanisms, and more. So it is clear that Open Source has a lot to offer Topic Maps. But what can Topic Maps offer to the Open Source community ?
1. As A Component - Topic maps could provide a basic data structure for implementing applications such as portals, personal and group knowledge management tools, content management systems and even for integrating information systems at a high level.
2. For Interchange - Topic maps structures are flexible enough to represent all kinds of interconnected data and could be used as an interchange syntax between knowledge management tools, diverse information systems, and web portals. Topic maps are designed to be merged, enabling applications to build not only interchange semantics but to incrementally add information to their store as they discover and interact with new partners.
3. Indexing Documentation - Topic maps provide a way to index a diverse collection of resources. Many open-source projects involve a lot of documentation: Javadoc, how-to, FAQ, plain old documentation, wikis and more. A topic map could provide the organisational framework to create a single unified view of all of these different resources, for example, allowing the class documentation to be linked to related FAQs and documentation
About the author. Kal Ahmed is an independent consultant and software developer. Kal has worked for many years with SGML and XML content management systems and more recently with semantic web technologies and especially topic maps. He is editor of part of ISO 13250, the ISO standard for topic maps, and is lead developer of TM4J, an open-source topic map processing library for Java, and TMTab, a charity-ware topic map editing tool. In what remains of his spare time he plays bass and annoys the neighbours.
XML is an enabler to the integration of the disparate database servers that exist in almost every organisation of any size. Properly utilised, it helps organisations to keep their data accessible, reusable and up to date, thereby maximising the return on investment of existing systems. In this way major system upgrades and replacements can be timed to suit the business need.
Like many good things, there is a danger that XML will become over-complicated and used for the wrong reasons. The XML standards have been intentionally developed as open standards. By utilising Open Source software and development tools such as Mono (www.go-mono.com) all are able to deploy XML solutions at reasonable cost, and without fear of being tied into a proprietary format. In this way everyone is able to benefit, not just a few first movers.
The presentation will examine a number of aspects of effective use of XML by developers. It will look at how XML Elements can map to a database. It will assess the benefits, such as the cross fertilisation of data and the searching capabilities with relational and OO databases. It will also look at using XML to update data in these databases. It will consider how developers can help users maximise their business use of data by harnessing the full power of XML and open source tools. It will examine the right development approach to provide feature-rich environments for both power users and standard desktop users, and the advantages of knowledge sharing. It will assess the methods of achieving best levels of security to keep the database administrator confident of data integrity and how to use XML to protect the database schematic. The benefits of using XML to map the database for schematic changes, without the requirement for additional application development will also be demonstrated.
The presentation will explain the importance of and benefits to developers and users of combining Open Source software development tools such as Mono and GCC with XML to create cross platform, user-friendly and secure database applications.
About the author.
Prior to TdZ, Simon consulted for SoftQuad Europe for several years, providing customer integrations and XML expertise. He co-wrote and delivered the first UK training course on XML and EDI, followed by many others, including a 3-day XML introductory course for IBM.
The open source community has been highly involved in developing for the RDF and related semantic web technologies applying them to many dynamic languages and for applications such as FOAF, image and geographic annotation, DOAP and OWL. This presentation will describe how the Redland family of RDF libraries work to provide high quality open source implementations of RDF across the native C and into 7 other dynamic languages. The focus will include how to deliver this in the best way for the open source community in terms of testing, packaging, maintenance and ensuring portability across systems, distributions and computer architectures.
About the author. Dave is a senior technical researcher at the Institute for Learning and Research Technology (ILRT), University of Bristol on the Semantic Web Advanced Development Europe project. He has worked with metadata and Dublin Core since 1995, RDF since 1998, was W3C RDF Core WG editor of the RDF/XML Syntax Recommendation, co-editor of RDF Test Cases Recommendation. Dave is the author of the open source Redland, Raptor and Rasqal RDF libraries and made the RDF Resource Guide and PlanetRDF.com
Why are one man's standards another man's anathema? NIH is not always to blame. This presentation will ponder many imponderables, including: What makes a standard a standard? How can you tell when to adopt a standard? Why don't we just rely on Open Software? Where can we get Open Standards? Why XML? Why not XML?...
As well as trying to convince you that you do need standards, Martin Bryan will be trying to convince you that the only way you can ensure that they meet your needs is to help to develop them, if only by reading and commenting thoughtfully on proposals while still at the drafting stage. Waiting until something is a Proposed Recommendation or a Final Draft is not the way to gain friends and influence people. Only by starting your arguments before positions have been taken by the protagonists can you hope to mould the next generation of standards to your needs.
About the author. Martin, Senior Technical Consultant at CSW group, has specialized in SGML and XML since 1985. A typesetter by training, Martin worked as an author, editor, production controller and typesetting systems tester for two decades before becoming Product Manager for the first SGML product suite to be developed in Europe. Since 1985 Martin has represented BSI on ISO committees evaluating document processing standards, and has served on the various ISO committees that have been responsible for the development of SGML, DSSSL, HyTime, Topic Maps and many other precursors to XML. In 1999 Martin helped create the first European test project on the combination of XML and EDI, a precursor to the development of ebXML as part of a CEN standardization initiative.
This presentation will
- Review the lessons learned by an XML developer grappling with RDF technology and tools.
- Highlight the common pitfalls that a likely to befall XML developers as they explore
- Address some common criticisms of RDF, and particularly reasons why developers may want to embrace the technology without necessarily having to buy into the grander visions of the semantic web.
About the author. Leigh is an application developer and designer specialising in Java, XML, and database design. He manages an small engineering team for Ingenta responsible for developing the document delivery systems supporting Ingenta.com. Leigh is also a freelance author and has contributed articles and tutorials to xmlhack, XML.com, and IBM developerWorks. Leigh is based in Bath, UK.
As a self describing format, XML offers possibilities for simplifying the versioning of an interface. A new version of an XML language may be designed to accept additional items and give any missing values a default value. An existing language processor may choose to simply ignore any new tags it doesn't understand. Unfortunately there are pitfalls to be avoided with this so-called 'passive' versioning in particular when processing XML based upon a description in XML Schema or a Web service interface described in WSDL. This topic will consider backwards and forwards compatibility in XML in particular the impacts of a change in semantics, discuss passive versus active versioning strategies, warn of the dangers from 'stove-pipes' (multiple pairs of tightly-coupled agents) and offer best practice in versioning XML languages. The implications of passive versioning in processing XML will be considered (possibly demonstrated) using several Open Source implementations: Apache Xerces, Apache Axis, Castor and XMLBeans.
About the author. Paul works with XML and Web services in the UK for BT Exact. He represents BT at the W3C and the WS-I, in particular particpating in the W3C WSDL Working Group. Over the course of the last 20 or so years he has worked for more than 14 different companies throughout in the UK and Europe, consulting and developing communications software and protocols.
DOAP (Description of a Project) is a free XML and RDF format and toolset that provides a computer-readable description of a software project's public resources.
Taking inspiration from the successful Friend-of-a-Friend project, DOAP allows project maintainers to write only one project description and allow it to be read by software registries such as Freshmeat, as well as any other interested party. Additionally, DOAP provides tools and mechanisms for many who wish to develop their own special purpose registries, or export data from existing registries.
In this presentation by the project leader, the goals and development process of DOAP will be described, with reference to forerunner web-wide vocabularies such as HTML, Dublin Core and RSS. As well as the technical details of the project itself, the presentation will cover the social and community aspects of getting such a project running and adopted, and demonstrate the emerging set of tools developed by open source participants in the DOAP project.
About the author. Edd is chair of the XML Europe conference. He is a long-time commentator on XML, and was managing editor of XML.com between 1999 and 2004. Edd is now Editor at Large for O'Reilly Network, where he continues his interest in XML and RDF, but also covers Linux and other free software topics. Edd develops free software and is a developer on the Debian GNU/Linux project. He has a weblog at http://usefulinc.com/edd/blog.
Topic maps have been described as information finding aids, but as we all know there is already a rich variety of such finding aids, so why should we be excited by the addition of yet another? Clearly there is no reason for excitement, unless the new finding aid brings something new into the equation.
This paper compares topic maps to existing content classification systems, to show whether whether topic maps have anything to offer beyond existing solutions, and whether these benefits come at a cost. The purpose is to give the reader a clearer understanding of how an ontology differs from traditional classification systems, and in what circumstances it can perform better as a finding aid.
It begins by looking at what metadata really is, and how metadata fails to solve the findability problem by failing to answer the question of "where do I find documents about X", which is what the user is really thinking when searching for information. Metadata does describe the document, but primarily in ways useful for document administration, and not in terms of the document's aboutness.
Classification systems, on the other hand, do address this issue, by creating named concepts, and attaching documents to the concepts they are about. This is one particular type of metadata, of course. There are many classification systems, and they differ primarily in how they describe the concepts in the system.
The paper then compares thesauri, taxonomies, and faceted classification with topic maps to show how topic maps have richer descriptive capabilities than the hierarchical alternatives, and how this makes them better finding aids. (It is also shown how the more limited classification systems can all be represented inside topic maps.)
Since topic maps can describe concepts better, it means that a topic map can scale to a larger number of concepts, and that it becomes much easier to find the concept used to classify the information one is looking for. The information about the concepts also makes it possible to find information more indirectly, through the information one has about each each concept.
Also, with topic maps, all the different kinds of metadata can be integrated together to form a complete solution to the findability problem, and this means that a much more powerful solution can be created.
The merging abilities of topic maps are not matched in existing classification systems, and the paper shows how this can be used to build more powerful classification systems by integrating information from diverse sources.
Finally, the effort required to create a topic map is compared with that required to create thesauri and other classification systems, and some consideration is given to in what circumstances the effort is justified.
About the author. Lars Marius is currently Development Manager at Ontopia, a topic map software vendor. He has been active in the XML and topic map communities as a speaker, consultant and open source developer for a number of years. Lars Marius has also been responsible for adding Unicode support to the Opera web browser. At the moment, he is completing his book on 'Developing XML Applications', published by Prentice-Hall in its Charles Goldfarb series in 2003. Lars Marius is one of the editors of the ISO Topic Map Query Language standard, as well as of the topic map data model.
XSLT 2.0 offers a wide range of new features, and of these the most controversial is the integration with XML Schema. Although schema-awareness is optional both for vendors and for users, achieving this integration changes the foundations of the language: its data model and type system. This talk, from the editor of the XSLT 2.0 specification, will describe the thinking behind this feature. It will demonstrate different ways in which an XSLT transformation can take advantage of information from the schema of the source or result document, to shorten the debugging cycle and potentially to give the XSLT optimizer more information to work with.
About the author. Michael is the editor of the XSLT 2.0 specification, the author of XSLT 2.0 Programmer's Reference and XPath 2.0 Programmer's Reference (about to be published by Wrox Press), and the developer of the well-known Saxon engine which now handles XML Schema as well as XSLT, XPath, and XQuery. He has recently created his own company, Saxonica, to continue the development of the Saxon technology. He is on his home territory at this conference, having gained his Ph.D at the Cambridge Computer Laboratory for research on database management systems.
As Web services have evolved as a means to integrate processes and applications at an inter-enterprise level, traditional transaction semantics and protocols have proven to be inappropriate. Web services-based transactions, colloquially termed Business Transactions, differ from traditional transactions in that they execute over long periods, they require commitments to the transaction to be “negotiated” at runtime, and isolation levels have to be relaxed.
A solution to this problem has to work over HTTP and include existing transaction processing technologies of all types: database management systems, application servers, message queuing systems and packaged applications. The solution needs to support a range of requirements including lightweight applications in which the major goal is to let Web services know when they’re in the same application to complicated transactions that may take days or weeks to complete across wide ranging geographies, time zones, and enterprise boundaries. In this presentation we’ll look at the OASIS WS-CAF standardization effort and show how it is attempting to address this important and difficult subject. We’ll also consider how the architecture defined by WS-CAF fits into the evolving architecture of Web services and give an indication of where we think things are going in the future.
About the author. Mark was a part of the core research team at the University of Newcastle where the first distributed object transaction system was developed. He co-founded Arjuna Solutions, a company specializing in transactional Java products, which was acquired by Bluestone Software and later Hewlett-Packard. He later led the Arjuna labs at Hewlett Packard Corporation. He has remained engaged with standards in the Java Community Process, OASIS, W3C and the OMG, and is the chief architect for Arjuna Technologies, a spin off from HP.
This talk will discuss open source from a business perspective. It will cover commercialization options, marketing strategies, and funding options, with reference to established businesses.
Open source businesses can be either service or product based, with a variety of monetization approaches including: service fees; dual source licensing; and commercial wrappers, connectors or components.
Markets can be addressed directly by creating products with end user licenses, or can be accessed indirectly through developers and OEM vendors.
Until recently external funding was not available, but companies like JBoss have shown that investors can be sold on an open source business model. Do intellectual property rights no longer matter? What's the exit strategy?
This talk will cover these topics in reference to companies that have used open source to their benefit, for example: Sleepycat, RedHat, MySQL, Sendmail, JBoss, Zope, Netscape, and Trolltech.
About the author. John has been a successful engineer, architect, and leader within technology companies both in the UK and US. He recently founded Parthenon Computing in Oxford and serves as its Technical Director. His prior experience includes working on projects at Microsoft, Lucent, Netscape, AOL, Sun, and Sleepycat. He continues his involvement with the ACCU as Publications Officer.
Details coming soon ...
About the author. Sean is CTO of Propylon. He is an internationally acknowledged authority on XML and related standards. He served as an invited expert to the W3C's Expert Group that defined XML in 1998. He is the author of three books on markup languages published by Prentice Hall and writes the weekly 'e-business in the enterprise' newsletter for ITWorld.
XML may be touted as a simple and clear way to convey information so that it can be quickly parsed and understood by both computers and humans. But it is possible to design a schema so that many of the advantages of XML are thrown away. In this talk, examples of poor design are given from real life and are used to illustrate principles which lead to better data structures, based on the presenter's experience with data modelling for security and resource metadata. Getting data design right is particuarly important in open source programming, which tends to take place in scattered teams where members may have different approaches.
About the author. Simon is currently the Senior Programmer for the Perseus project, based at the London School of Economics. This is the latest in a series of middleware software projects with which he has been involved. He created the UKeduPerson schema, and designed security and resource metadata. He has been developing open source software which uses XML since 1998 in UK, European and worldwide project contexts. He is also an Associate Lecturer with the Open University.
Access control policies for XML typically use regular path expressions such as XPath for specifying the objects for access control policies. However such access control policies are burdens to the engines for XML query languages. To relieve this burden, we introduce static analysis for XML access control. Given an access control policy, query expression, and an optional schema, static analysis determines if this query expression is guaranteed not to access elements or attributes that are permitted by the schema but hidden by the access control policy. Static analysis can be performed without evaluating any query expression against an actual database. Run-time checking is required only when static analysis is unable to determine whether to grant or deny access requests. A nice side-effect of static analysis is query optimization: access-denied expressions in queries can be evaluated to empty lists at compile time. We have built a prototype of static analysis for XQuery, and shown the effectiveness and scalability through experiments.
About the author. Murata is a co-editor of the RELAX NG specifications of OASIS, the editor of its predecessor, RELAX Core of ISO/IEC, and the editor of ISO/IEC DSDL Part 4. He has been promoting hedge or tree automata as formal models for schemas since 1994. He was a member of the original XML WG, co-editor of media-type RFCs for XML, and the editor of the Japanese XML Profile.
XML forms sound great on paper – abstraction of UI mechanics from presentation logic, cross-environment interop, everything in clean XML – but what are they like in practice? Which species of “XML Forms” should we choose? What O/S tools are out there? What works, and what doesn't? We needed some answers to these questions, so we decided to go hunting - this paper is a blog of our trip.
We've got so used to the integrated flows that we can build with XML pipelining that it's a rude shock when people get involved. We have to build user interfaces (again), validate user input (again), deliver results in an intelligible format (again). With XML forms technologies we get the tantalising prospect of having the whole process, including the user interaction, handled entirely in XML. All the good things that lightweight XML brought to server side development can potentially extend to the UI as well. Is this just a pipedream? Mozilla Firefox and Thunderbird suggest not. So how can we turn it into practical reality?
This is a practical description of our hunting trip through the lands of XForms, Cocoon Forms and Mozilla XUL, with some trophies we brought back with us and a few things we've promised never, ever, to do again.
About the author. Thomas has been developing commercial software since he caught the OO bug in 1986, and saw the advent of XML in 1998 as his escape from EDI. His interest throughout his career has been in practical implementation of rocket-science technology to solve real-world problems, he is now greatly enjoying putting his commercial experience into practice steering the technical implementation of DeltaXML, which he sees as a revolutionary technology. Thomas is a skilled Java and C++ programmer, working with cross-platform technologies and happiest in a "heterogeneous environment". XML is one of his very favourite beasts.
Apache Cocoon (http://cocoon.apache.org/) is an open source framework for Java web application development, known for its good support of XML and related standards. Cocoon's main differentiator with other frameworks is a strong separation of concerns, enabling larger project teams to work on complicated projects without clashes. Cocoon's core consists of a central configuration and dispatching component, an XML pipelining mechanism, sophisticated form handling and a continuations-based scripting component for directing the flow of a web application. Cocoon also contains a built-in portal framework and a wealth of other integration and data-access components. This presentation gives an overview of the most important aspects of Cocoon with a special focus on interactive web applications.
About the author. Steven is Managing Partner of Outerthought, an Open Source Java and XML knowledge support center. Outerthought coaches development teams to make more effective use of Java and XML, with a special focus on Apache Cocoon and open source development practices. Steven is member of the Apache Software Foundation and a regular speaker on both local and international conferences. Besides all this, Steven's prime interests are the social dynamics in open source software teams, digital photography, blue-sky day-dreaming and indulging a happy family life thanks to his partner and three kids.
Python is a very popular language for processing XML because of its flexibility, and the work of many open-source developers in the XML-SIG and elsewhere. The most popular XML processing models, DOM and SAX are well-represented, and many other important technologies from XSLT and XPath through RDF.
But the real strength of Python for XML processing requires specialized models to emerge. The dynamicism of Python allows for next-generation data bindings that use declarative forms for mirroring XML vocabularies. The combination of Python and XML core strengths could provide even more power, registering XPatterns for dispatch during parsing and XPaths for triggering of processing. Python's strengths in introspection allow for simplified serialization to XML. Its variety of polymorphic hooks allow for pluggable datatype libraries, among other advantages. These strengths add up to especially rich forms of data-binding that do not depend on an object or relational view of XML data.
This presentation is an overview of the many XML processing tools and techniques available for Python, and focuses especially on tools that make the most of the Python's strengths in XML processing.
About the author. Uche is a Computer Engineer, co-founder and CEO of Fourthought. He has over a decade's experience in professional consulting on software development, data design and distributed systems. He has worked with XML since early 1998, and in Web Services since late 2000. He also co-develops 4Suite, an open-source platform for XML and RDF processing. He is lead designer of the Versa query language for RDF, and several other influential technical reports. He is a columnist for IBM developerWorks, Application Development Trends and XML.com. He has written over 100 articles on XML, Web Services and RDF in recognized publications and speaks extensively at conferences worldwide. He was invited to provide his expert perspective on the role of Semantic Web technologies at the W3C's Web Services Workshop in 2001, where the Web Services activity of the W3C was scoped and planned. He received the 2003 ActiveState Active Award for outstanding contribution in the profession of software development in the topic of XSLT.
Fourthought, Inc. is a consultancy that helps clients generate value from XML and other Web technologies, through assistance in technology strategy and software development. Some recent clients include Sun Microsystems, Colorado Department of State, SAIC, US Naval Surface Warfare Center, Phillips Petroleum, and Quovadx.
Educational institutions are being increasingly urged to go open source. The research funding bodies ask for open source licenses on software being generated; UK and European governments push open source as a positive choice; consortially-funded e-learning frameworks are this year's fashion; budget pressures make the "free beer" aspect of open source increasingly attractive. Supporting this is the almost universal acceptance of XML for data interchange. So why do so few institutions have a positive commitment to open source, and pay little more than lip service to open standards?
This talk will describe some of the work done by OSS Watch in investigating the state of open source in UK higher and further education, and outline what we think the difficulties are, and how they can be overcome. As part of this, we showcase OSS Watch's own commitment to XML-based workflows, and discuss why we find it hard to persuade other people to do the same.
About the author. Sebastian has been in and around computers, publishing and information for the last 20 years. He is currently manager of the JISC-funded Open Source Advisory Service, on secondment from being Information Manager for Oxford University Computing Services; in both roles he concerns himself with XML-based web sites, portals, and the like.
This presentation's subject is the development of 1060 NetKernel - an open-source XML Application Server. We will start with its origins at Hewlett-Packard and the industrial context of intra-industry XML messaging. We shall then explore its technical and commercial evolution to an independent service-oriented operating environment.
To conclude we shall present some observations on the relationship between open-source and the adoption of new XML technologies.
About the author. Peter is the founder and CEO of 1060 Research and architect of the 1060 NetKernel XML Application Server. Prior to starting 1060 he established and led Hewlett-Packard's XML research programme and provided strategic consultancy to Hewlett Packard’s software businesses. Peter holds a PhD in solid-state quantum mechanics from the University of Nottingham.
This presentation looks at some of the practical issues which might arise in implementing an XForms-based application. It includes a review of techniques, strategies, tools and obstacles to success, and looks in detail at a specific prototype implementation. Finally, there will be an assessment of the prospect of XForms acquiring mainstream acceptability, and surviving the competitive assaults of big name proprietary alternatives.
XForms became a W3C recommendation in October 2003. The session will begin with a reminder of its purpose and underpinning principles, and a short demonstration of XForms in action.
The core of the presentation will focus on some of the common requirements that XForms could be in a position to address, examining and critically evaluating possible approaches to key issues such as:
- Forms authoring and maintenance – how do we build an XForms interface, and what skills will be required to do it?
- User interface design and behaviours – how far does XForms go towards giving us the richness of interface that users expect?
- Implementation technologies – what tools are available for us to design, build and implement XForms applications – and do they work?
- Systems integration and interoperability – how will XForms fit within existing XML and web architectures and standards?
- Device independence – how well will XForms deliver interactive interfaces to a diverse range of user devices – for example, browsers, PDAs?
- Security and authentication – is XForms capable of operating in a secure environment?
This part of the presentation will be illustrated with examples from a prototype XForms project, showing the use of XForms tools, and XForms integrated with other technologies – for example Microsoft Sharepoint, and RSS feed generation.
The presentation will conclude with an assessment of the positioning of XForms with respect to competing approaches, and a review of the factors and circumstances that will determine its success or failure in the marketplace.
About the author. Antony is the Technical Director at RivCom Ltd. He has been developing XML-based applications in support of RivCom's services for six years, and has over ten years of experience both in writing and publishing structured documentation. Antony has spoken at a number of industry conferences including XML Europe and XMLOne, and run training in XML for a range of organisations, including Shell and the UK Public Record Office. He has an MSc in Administration, Design and Management of Information Systems from the London School of Economics.
The Semantic Web applications are going from prototype to deployment. One reason for this is the availability of high quality, open source frameworks which implement the W3C recommendations. Applications developers working in the integration and organisation of information can concentrate on their applications, knowing that common software takes care of correct implementation of the W3C recommendations.
One such framework for Java is Jena, from HPlabs. At the RDF level, Jena provides input and output, taking care of the RDF/XML syntax and gives a rich set of APIs for working with RDF. At the next level, Jena provides an ontology API for working with OWL and RDFS allowing Java programmers to conveniently build and traverse ontologies. All these are back by storage in-memory and persistent in relational databases.
Jena has a rules engine for application specific rule sets and standard rule sets for the OWL-lite/RDFS subset. For heavy-duty ontology work, external inference engines can be plugged-in.
These APIs are complemented by query access, and by an RDF WebAPI for publishing information. Jena's RDF Server, Joseki, provides a first generation server for the publishing and reuse of information on the Semantic Web.
About the author. Andy is a research scientist in the Hewlett-Packard Semantic Web programme. He specialises in the areas of query and remote access for Semantic Web knowledge bases. He is HP's primary participant in the W3C RDF Data Access Working Group and had authored key member submissions to W3C in this area. He has worked in areas related to applied distributed system applied including distributed object systems, telecoms systems and now the Semantic Web.
W3C XML Schema defines a set of datatypes based on those found in programming languages and database products. But this isn't what we need when validating and processing XML.
In this presentation, we'll survey the range of datatypes that are actually being used in existing markup languages. We'll look at how W3C XML Schema fails us by supporting only a fraction of these datatypes. Finally, we'll consider a lexical datatyping approach that could offer a way forward.
About the author. Jeni Tennison is an Independent Consultant specialising in XSLT and XML schema development. She trained as a knowledge engineer, gaining a PhD in collaborative ontology development, and since becoming a consultant has worked in a wide variety of areas, including publishing, water monitoring and financial services. She is author of "XPath On The Edge" (Hungry Minds, 2001) and "XSLT" (Wrox, 2002) and one of the founders of the EXSLT initiative to standardise extensions to XSLT and XPath.
There's a crisis at the heart of the Semantic Web, summarised by the following quote:
"claiming that 'http' URIs are [whatever] does nothing to solve the question of what some person is actually referring to when they make a link using an 'http' URI."
When you, or more to the point, a program, see the following:
http://www.w3.org/People/thompson/
http://purl.org/dc/elements/1.1/creator
http://www.ltg.ed.ac.uk/~ht/
how do you know that this means "HST's W3C home page [what is meant by http://www.w3.org/People/thompson/] was created by HST [what is meant by http://www.ltg.ed.ac.uk/~ht/]? That is, how do you know when a URI is about a web page, and when its about what that web page itself is about?
In this talk I'll present a new idea, Web Proper Names, intended to solve this problem. Web Proper Names
- Provide a distributed approach to creating and sharing Web names for things;
- Allow use of Web names as names to be easily distinguished from the use of URIs to address web pages;
- Allows for efficient and reliable determination of whether two URIs address web pages which describe the same thing;
- Does not require a single canonical name, while still achieving interoperability of names.
About the author. Henry S. Thompson divides his time between the School of Informatics at the University of Edinburgh, where he is Reader in Artificial Intelligence and Cognitive Science, based in the Language Technology Group of the Human Communication Research Centre, and the World Wide Web Consortium (W3C), where he works in the XML Activity.
His research interests have ranged widely, including natural language parsing, speech recognition, machine translation evaluation, modelling human lexical access mechanisms, the fine structure of human-human dialogue, language resource creation and architectures for linguistic annotation. His current research is focussed on articulating and extending the architectures of XML.
He was a member of the SGML Working Group of the World Wide Web Consortium which designed XML, is the author of the XED, the first free XML instance editor and co-author of the LT XML toolkit and is currently a member of the XSL and XML Schema Working Groups of the W3C. He is lead editor of the Structures part of the XML Schema W3C Recommendation, for which he co-wrote the first publicly available implementation, XSV. He has presented many papers and tutorials on SGML, DSSSL, XML, XSL and XML Schemas in both industrial and public settings over the last eight years.
The notion of "validation" of XML documents covers too many different aspects (structure, content, integrity, business rules, ...) to be performed by a single schema language.
Furthermore, even when a single language is used, it is often the case that documents need to be transformed, split or normalized to keep the schemas simpler.
The ISO DSDL project (ISO/IEC JTC 1 SC 34 WG 1) is standardizing a set of specific and simple schema and pre-validation transformation languages and a framework to define how these operations must be applied. These languages include well known technologies such as Relax NG and Schematron as well as new languages.
This talk will give a full project overview, explaining the goal of each of the parts and present the latest developments of DSDL.
About the author. In 1997 Alex Brown was one of the founding directors of Griffin Brown Digital Publishing Ltd, a company which provides XML-based components and tools - chiefly to the publishing industry. He is responsible for leading the company’s XML consulting and implementation, and his work includes advising clients on XML/IT strategy, mentoring clients’ staff, writing DTDs and Schemas, and designing and developing XML software systems in Java, C++ and other languages.
Alex had an unorthodox path to XML: he read English Literature at the University of Bristol (UK), and gained a Ph.D. for his work on Shakespeare editions. Following a brief and unsatisfying spell in academia he revived his teenage interest in software development and spent four interesting years working on heavily object-oriented C++ application framework for cross-platform multimedia products.
Alex is a member of the BSI Technical Committee IST/41, working on the UK contribution to the formation of the DSDL ISO standard, among other things.
Groovy is a new scripting language which runs on the Java Virtual Machine. Groovy is being standardised using the Java Community Process. It it is a concise and powerful language which is easy to learn. This talk introduces Groovy's built in mechanisms to produce and consume XML documents. It shows how Groovy is being used to enhance and, in some cases replace, XML configuration files for Java applications. Learn how to use Groovy templates to produce simple XML documents quickly and Groovy Builders to produce complex XML documents easily. Learn how GPath can extract data from XML documents and perform transformations on that data. Learn how the Java Community Process is being used by an Open Source project to create a new standard.
About the author. John Wilson has over 30 years experience in IT. An early adopter of both Java and XML technologies, he has founded and contributed to many Open Source projects. He is an active member of the Groovy project and is the author of "Groovy in Action" to be published by Manning in 2005
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