Graph Hierarchy

Unidirected Graph with "spring" models (Kamada and Kawai, Information Processing Letters 31:1, April 1989)

Graph with a radial layout (G. Wills, Symposium on Graph Drawing GD'97, Settember 1997). One node is chosen as the center and put at the origin. The remaining nodes are placed on a sequence of concentric circles centered about the origin, each a fixed radial distance from the previous circle. All nodes distance 1 from the center are placed on the first circle; all nodes distance 1 from a node on the first circle are placed on the second circle; and so forth.

Graph with a circular layout (Six and Tollis, GD '99 and ALENEX '99 and Kaufmann and Wiese, GD '02). The tool identifies biconnected components and draws the nodes of the component on a circle. The block-cutpoint tree is then laid out using a recursive radial algorithm. Edge crossings within a circle are minimized by placing as many edges on the circle's perimeter as possible. In particular, if the component is outerplanar, the component will have a planar layout.

Graph with a "spring" model. It relies on a force-directed approach in the spirit of Fruchterman and Reingold (Software-Practice & Experience 21(11), 1991, pp. 1129-1164).

This specification provides guidelines for Web authoring tool developers. Its purpose is two-fold: to assist developers in designing authoring tools that produce accessible Web content and to assist developers in creating an accessible authoring interface.

Authoring tools can enable, encourage, and assist users ("authors") in the creation of accessible Web content through prompts, alerts, checking and repair functions, help files and automated tools. It is just as important that all people be able to author content as it is for all people to have access to it. The tools used to create this information must therefore be accessible themselves. Adoption of these guidelines will contribute to the proliferation of Web content that can be read by a broader range of readers and authoring tools that can be used by a broader range of authors.

This document describes CC/PP (Composite Capabilities/Preference Profiles) structure and vocabularies. A CC/PP profile is a description of device capabilities and user preferences. This is often referred to as a device's delivery context and can be used to guide the adaptation of content presented to that device.

The Resource Description Framework (RDF) is used to create profiles that describe user agent capabilities and preferences. The structure of a profile is discussed. Topics include:

• structure of client capability and preference descriptions, AND
• use of RDF classes to distinguish different elements of a profile, so that a schema-aware RDF processor can handle CC/PP profiles embedded in other XML document types.

CC/PP vocabulary is identifiers (URIs) used to refer to specific capabilities and preferences, and covers:

• the types of values to which CC/PP attributes may refer,
• an appendix describing how to introduce new vocabularies,
• an appendix giving an example small client vocabulary covering print and display capabilities, and
• an appendix providing a survey of existing work from which new vocabularies may be derived.

This document specifies level 1 of the Cascading Style Sheet mechanism (CSS1). CSS1 is a simple style sheet mechanism that allows authors and readers to attach style (e.g. fonts, colors and spacing) to HTML documents. The CSS1 language is human readable and writable, and expresses style in common desktop publishing terminology.

One of the fundamental features of CSS is that style sheets cascade; authors can attach a preferred style sheet, while the reader may have a personal style sheet to adjust for human or technological handicaps. The rules for resolving conflicts between different style sheets are defined in this specification.

This specification defines Cascading Style Sheets, level 2 (CSS2). CSS2 is a style sheet language that allows authors and users to attach style (e.g., fonts, spacing, and aural cues) to structured documents (e.g., HTML documents and XML applications). By separating the presentation style of documents from the content of documents, CSS2 simplifies Web authoring and site maintenance.

CSS2 builds on CSS1 and, with very few exceptions, all valid CSS1 style sheets are valid CSS2 style sheets. CSS2 supports media-specific style sheets so that authors may tailor the presentation of their documents to visual browsers, aural devices, printers, braille devices, handheld devices, etc. This specification also supports content positioning, downloadable fonts, table layout, features for internationalization, automatic counters and numbering, and some properties related to user interface.

This specification defines the Document Object Model Level 1, a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure and style of documents. The Document Object Model provides a standard set of objects for representing HTML and XML documents, a standard model of how these objects can be combined, and a standard interface for accessing and manipulating them. Vendors can support the DOM as an interface to their proprietary data structures and APIs, and content authors can write to the standard DOM interfaces rather than product-specific APIs, thus increasing interoperability on the Web.

The goal of the DOM specification is to define a programmatic interface for XML and HTML. The DOM Level 1 specification is separated into two parts: Core and HTML. The Core DOM Level 1 section provides a low-level set of fundamental interfaces that can represent any structured document, as well as defining extended interfaces for representing an XML document. These extended XML interfaces need not be implemented by a DOM implementation that only provides access to HTML documents; all of the fundamental interfaces in the Core section must be implemented. A compliant DOM implementation that implements the extended XML interfaces is required to also implement the fundamental Core interfaces, but not the HTML interfaces. The HTML Level 1 section provides additional, higher-level interfaces that are used with the fundamental interfaces defined in the Core Level 1 section to provide a more convenient view of an HTML document. A compliant implementation of the HTML DOM implements all of the fundamental Core interfaces as well as the HTML interfaces.

This specification defines the Document Object Model Level 2 Core, a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content and structure of documents. The Document Object Model Level 2 Core builds on the Document Object Model Level 1 Core. The DOM Level 2 Core is made of a set of core interfaces to create and manipulate the structure and contents of a document. The Core also contains specialized interfaces dedicated to XML.

This specification defines the Document Object Model Level 2 Events, a platform- and language-neutral interface that gives to programs and scripts a generic event system. The Document Object Model Level 2 Events builds on the Document Object Model Level 2 Core and on Document Object Model Level 2 Views.

This specification defines the Document Object Model Level 2 HTML, a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content and structure of html 4.01 and XHTML 1.0 documents. The Document Object Model Level 2 HTML builds on the Document Object Model Level 2 Core and is not backward compatible with DOM Level 1 HTML.

This specification defines the Document Object Model Level 2 Style Sheets and Cascading Style Sheets (CSS), a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content and of style sheets documents. The Document Object Model Level 2 Style builds on the Document Object Model Level 2 Core and on the Document Object Model Level 2 Views.

This specification defines the Document Object Model Level 2 Traversal and Range, platform- and language-neutral interfaces that allow programs and scripts to dynamically traverse and identify a range of content in a document. The Document Object Model Level 2 Traversal and Range build on the Document Object Model Level 2 Core. The DOM Level 2 Traversal and Range specification is composed of two modules. The two modules contain specialized interfaces dedicated to traversing the document structure and identifying and manipulating a range in a document.

This specification defines the Document Object Model Level 2 Views, a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content of a representation of a document. The Document Object Model Level 2 Views builds on the Document Object Model Level 2 Core.

This specification defines the Document Object Model Core Level 3, a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure and style of documents. The Document Object Model Core Level 3 builds on the Document Object Model Core Level 2. This version enhances DOM Level 2 Core by completing the mapping between DOM and the XML Information Set XML Information Set, including the support for XML Base [XML Base], adding the ability to attach user information to DOM Nodes or to bootstrap a DOM implementation, providing mechanisms to resolve namespace prefixes or to manipulate "ID" attributes, giving to type information, etc.

This specification defines the Document Object Model Load and Save Level 3, a platform- and language-neutral interface that allows programs and scripts to dynamically load the content of an XML document into a DOM document and serialize a DOM document into an XML document; DOM documents being defined in DOM Level 2 Core or newer, and XML documents being defined in XML 1.0 or newer. It also allows filtering of content at load time and at serialization time.

This specification defines the Document Object Model Validation Level 3, a platform- and language-neutral interface. This module provides the guidance to programs and scripts to dynamically update the content and the structure of documents while ensuring that the document remains valid, or to ensure that the document becomes valid.

The W3C Digital Signature Working Group (quot;DSigquot;) proposes a standard format for making digitally-signed, machine-readable assertions about a particular information resource. PICS 1.1 labels are an example of such machine-readable assertions. This document describes a method of adding extensions to PICS 1.1 labels for purposes of signing them. More generally, it is the goal of the DSig project to provide a mechanism to make the statement: signer believes statement about information resource. In DSig 1.0 statement is any statement that can be expressed with PICS 1.1.

This specification defines the Mathematical Markup Language, or MathML. MathML is an XML application for describing mathematical notation and capturing both its structure and content. The goal of MathML is to enable mathematics to be served, received, and processed on the Web, just as HTML has enabled this functionality for text.

This specification of the markup language MathML is intended primarily for a readership consisting of those who will be developing or implementing renderers or editors using it, or software that will communicate using MathML as a protocol for input or output. It is not a User's Guide but rather a reference document.

This document begins with background information on mathematical notation, the problems it poses, and the philosophy underlying the solutions MathML proposes. MathML can be used to encode both mathematical notation and mathematical content. Twenty-eight of the MathML tags describe abstract notational structures, while another seventy-five provide a way of unambiguously specifying the intended meaning of an expression. Additional chapters discuss how the MathML content and presentation elements interact, and how MathML renderers might be implemented and should interact with browsers. Finally, this document addresses the issue of MathML entities (extended characters) and their relation to fonts.

While MathML is human-readable it is anticipated that, in all but the simplest cases, authors will use equation editors, conversion programs, and other specialized software tools to generate MathML. Several early versions of such MathML tools already exist, and a number of others, both freely available software and commercial products, are under development.

This specification defines the Mathematical Markup Language, or MathML. MathML is an XML application for describing mathematical notation and capturing both its structure and content. The goal of MathML is to enable mathematics to be served, received, and processed on the World Wide Web, just as HTML has enabled this functionality for text.

This specification of the markup language MathML is intended primarily for a readership consisting of those who will be developing or implementing renderers or editors using it, or software that will communicate using MathML as a protocol for input or output. It is not a User's Guide but rather a reference document.

This document begins with background information on mathematical notation, the problems it poses, and the philosophy underlying the solutions MathML 2.0 proposes. MathML can be used to encode both mathematical notation and mathematical content. About thirty of the MathML tags describe abstract notational structures, while another about one hundred and fifty provide a way of unambiguously specifying the intended meaning of an expression. Additional chapters discuss how the MathML content and presentation elements interact, and how MathML renderers might be implemented and should interact with browsers. Finally, this document addresses the issue of MathML characters and their relation to fonts.

While MathML is human-readable, it is anticipated that, in all but the simplest cases, authors will use equation editors, conversion programs, and other specialized software tools to generate MathML. Several versions of such MathML tools already exist, and a number of others, both freely available software and commercial products, are under development.

This is the specification of the Platform for Privacy Preferences (P3P). This document, along with its normative references, includes all the specification necessary for the implementation of interoperable P3P applications.

This document specifies the second version of the Synchronized Multimedia Integration Language (SMIL, pronounced "smile"). SMIL 2.1 has the following design goals:

• Define an XML-based language that allows authors to write interactive multimedia presentations. Using SMIL, an author can describe the temporal behaviour of a multimedia presentation, associate hyperlinks with media objects and describe the layout of the presentation on a screen.
• Allow reusing of SMIL syntax and semantics in other XML-based languages, in particular those who need to represent timing and synchronization. For example, SMIL components are used for integrating timing into XHTML and into SVG.
• Extend the functionalities contained in the SMIL 2.0 into new or revised SMIL 2.1 modules.
• Define new SMIL 2.1 Mobile Profiles incorporating features useful within the mobile industry.

This specification defines the features and syntax for Scalable Vector Graphics (SVG) Version 1.1, a modularized language for describing two-dimensional vector and mixed vector/raster graphics in XML.

This document defines two mobile profiles of SVG 1.1. The first profile, SVG Tiny, is defined to be suitable for cellphones; the second profile, SVG Basic, is suitable for PDAs.

This document provides guidelines for designing user agents that lower barriers to Web accessibility for people with disabilities (visual, hearing, physical, cognitive, and neurological). User agents include HTML browsers and other types of software that retrieve and render Web content. A user agent that conforms to these guidelines will promote accessibility through its own user interface and through other internal facilities, including its ability to communicate with other technologies (especially assistive technologies). Furthermore, all users, not just users with disabilities, should find conforming user agents to be more usable.

In addition to helping developers of HTML browsers and media players, this document will also benefit developers of assistive technologies because it explains what types of information and control an assistive technology may expect from a conforming user agent. Technologies not addressed directly by this document (e.g., technologies for braille rendering) will be essential to ensuring Web access for some users with disabilities.

These guidelines explain how to make Web content accessible to people with disabilities. The guidelines are intended for all Web content developers (page authors and site designers) and for developers of authoring tools. The primary goal of these guidelines is to promote accessibility. However, following them will also make Web content more available to all users, whatever user agent they are using (e.g., desktop browser, voice browser, mobile phone, automobile-based personal computer, etc.) or constraints they may be operating under (e.g., noisy surroundings, under- or over-illuminated rooms, in a hands-free environment, etc.). Following these guidelines will also help people find information on the Web more quickly. These guidelines do not discourage content developers from using images, video, etc., but rather explain how to make multimedia content more accessible to a wide audience.

This is a reference document for accessibility principles and design ideas. Some of the strategies discussed in this document address certain Web internationalization and mobile access concerns. However, this document focuses on accessibility and does not fully address the related concerns of other W3C Activities. Please consult the W3C Mobile Access Activity home page and the W3C Internationalization Activity home page for more information.

This document is meant to be stable and therefore does not provide specific information about browser support for different technologies as that information changes rapidly. Instead, the Web Accessibility Initiative (WAI) Web site provides such information.

This document includes an appendix that organizes all of the checkpoints by topic and priority. The checkpoints in the appendix link to their definitions in the current document. The topics identified in the appendix include images, multimedia, tables, frames, forms, and scripts. The appendix is available as either a tabular summary of checkpoints or as a simple list of checkpoints.

A separate document, entitled quot;Techniques for Web Content Accessibility Guidelines 1.0quot;, explains how to implement the checkpoints defined in the current document. The Techniques Document discusses each checkpoint in more detail and provides examples using the Hypertext Markup Language (HTML), Cascading Style Sheets (CSS), Synchronized Multimedia Integration Language (SMIL), and the Mathematical Markup Language (MathML). The Techniques Document also includes techniques for document validation and testing, and an index of HTML elements and attributes (and which techniques use them). The Techniques Document has been designed to track changes in technology and is expected to be updated more frequently than the current document. Note. Not all browsers or multimedia tools may support the features described in the guidelines. In particular, new features of HTML 4.0 or CSS 1 or CSS 2 may not be supported.

quot;Web Content Accessibility Guidelines 1.0quot; is part of a series of accessibility guidelines published by the Web Accessibility Initiative. The series also includes User Agent Accessibility Guidelines and Authoring Tool Accessibility Guidelines.

This specification defines the HyperText Markup Language (HTML), the publishing language of the World Wide Web. This specification defines HTML 4.01, which is a subversion of HTML 4. In addition to the text, multimedia, and hyperlink features of the previous versions of HTML (HTML 3.2 and HTML 2.0), HTML 4 supports more multimedia options, scripting languages, style sheets, better printing facilities, and documents that are more accessible to users with disabilities. HTML 4 also takes great strides towards the internationalization of documents, with the goal of making the Web truly World Wide.

HTML 4 is an SGML application conforming to International Standard ISO 8879 -- Standard Generalized Markup Language.

This specification defines the HyperText Markup Language (HTML), the publishing language of the World Wide Web. This specification defines HTML 4.01, which is a subversion of HTML 4. In addition to the text, multimedia, and hyperlink features of the previous versions of HTML (HTML 3.2 and HTML 2.0), HTML 4 supports more multimedia options, scripting languages, style sheets, better printing facilities, and documents that are more accessible to users with disabilities. HTML 4 also takes great strides towards the internationalization of documents, with the goal of making the Web truly World Wide.

HTML 4 is an SGML application conforming to International Standard ISO 8879 -- Standard Generalized Markup Language.

The OWL Web Ontology Language is designed for use by applications that need to process the content of information instead of just presenting information to humans. OWL facilitates greater machine interpretability of Web content than that supported by XML, RDF, and RDF Schema (RDF-S) by providing additional vocabulary along with a formal semantics. OWL has three increasingly-expressive sublanguages: OWL Lite, OWL DL, and OWL Full.

This document is written for readers who want a first impression of the capabilities of OWL. It provides an introduction to OWL by informally describing the features of each of the sublanguages of OWL. Some knowledge of RDF Schema is useful for understanding this document, but not essential. After this document, interested readers may turn to the OWL Guide for more detailed descriptions and extensive examples on the features of OWL. The normative formal definition of OWL can be found in the OWL Semantics and Abstract Syntax.

The World Wide Web as it is currently constituted resembles a poorly mapped geography. Our insight into the documents and capabilities available are based on keyword searches, abetted by clever use of document connectivity and usage patterns. The sheer mass of this data is unmanageable without powerful tool support. In order to map this terrain more precisely, computational agents require machine-readable descriptions of the content and capabilities of Web accessible resources. These descriptions must be in addition to the human-readable versions of that information.

The OWL Web Ontology Language is intended to provide a language that can be used to describe the classes and relations between them that are inherent in Web documents and applications.

This document demonstrates the use of the OWL language to

• formalize a domain by defining classes and properties of those classes,
• define individuals and assert properties about them, and
• reason about these classes and individuals to the degree permitted by the formal semantics of the OWL language.

The sections are organized to present an incremental definition of a set of classes, properties and individuals, beginning with the fundamentals and proceeding to more complex language components.

The Web Ontology Language OWL is a semantic markup language for publishing and sharing ontologies on the World Wide Web. OWL is developed as a vocabulary extension of RDF (the Resource Description Framework) and is derived from the DAML+OIL Web Ontology Language. This document contains a structured informal description of the full set of OWL language constructs and is meant to serve as a reference for OWL users who want to construct OWL ontologies.

This description of OWL, the Web Ontology Language being designed by the W3C Web Ontology Working Group, contains a high-level abstract syntax for both OWL DL and OWL Lite, sublanguages of OWL. A model-theoretic semantics is given to provide a formal meaning for OWL ontologies written in this abstract syntax. A model-theoretic semantics in the form of an extension to the RDF semantics is also given to provide a formal meaning for OWL ontologies as RDF graphs (OWL Full). A mapping from the abstract syntax to RDF graphs is given and the two model theories are shown to have the same consequences on OWL ontologies that can be written in the abstract syntax.

This document contains and presents test cases for the Web Ontology Language (OWL) approved by the Web Ontology Working Group. Many of the test cases illustrate the correct usage of the Web Ontology Language (OWL), and the formal meaning of its constructs. Other test cases illustrate the resolution of issues considered by the Working Group. Conformance for OWL documents and OWL document checkers is specified.

The Resource Description Framework (RDF) is a framework for representing information in the Web.

RDF Concepts and Abstract Syntax defines an abstract syntax on which RDF is based, and which serves to link its concrete syntax to its formal semantics. It also includes discussion of design goals, key concepts, datatyping, character normalization and handling of URI references.

This is a specification of a precise semantics, and corresponding complete systems of inference rules, for the Resource Description Framework (RDF) and RDF Schema (RDFS).

The Resource Description Framework (RDF) is a language for representing information about resources in the World Wide Web. This Primer is designed to provide the reader with the basic knowledge required to effectively use RDF. It introduces the basic concepts of RDF and describes its XML syntax. It describes how to define RDF vocabularies using the RDF Vocabulary Description Language, and gives an overview of some deployed RDF applications. It also describes the content and purpose of other RDF specification documents.

The Resource Description Framework (RDF) is a general-purpose language for representing information in the Web. This specification describes how to use RDF to describe RDF vocabularies. This specification defines a vocabulary for this purpose and defines other built-in RDF vocabulary initially specified in the RDF Model and Syntax Specification.

The Resource Description Framework (RDF) is a general-purpose language for representing information in the Web.

This document defines an XML syntax for RDF called RDF/XML in terms of Namespaces in XML, the XML Information Set and XML Base. The formal grammar for the syntax is annotated with actions generating triples of the RDF graph as defined in RDF Concepts and Abstract Syntax. The triples are written using the N-Triples RDF graph serializing format which enables more precise recording of the mapping in a machine processable form. The mappings are recorded as tests cases, gathered and published in RDF Test Cases.

This document describes the RDF Test Cases deliverable for the RDF Core Working Group as defined in the Working Group's Charter.

Ruby are short runs of text alongside the base text, typically used in East Asian documents to indicate pronunciation or to provide a short annotation. This specification defines markup for ruby, in the form of an XHTML module.

This document specifies version 1 of the Synchronized Multimedia Integration Language (SMIL 1.0, pronounced "smile"). SMIL allows integrating a set of independent multimedia objects into a synchronized multimedia presentation. Using SMIL, an author can

• describe the temporal behavior of the presentation
• describe the layout of the presentation on a screen
• associate hyperlinks with media objects

This specification is structured as follows: Section 1 presents the specification approach. Section 2 defines the "smil" element. Section 3 defines the elements that can be contained in the head part of a SMIL document. Section 4 defines the elements that can be contained in the body part of a SMIL document. In particular, this Section defines the time model used in SMIL. Section 5 describes the SMIL DTD.

This is a W3C Recommendation of a specification of animation functionality for XML documents. It describes an animation framework as well as a set of base XML animation elements suitable for integration with XML documents. It is based upon the SMIL 1.0 timing model, with some extensions, and is a true subset of SMIL 2.0. This provides an intermediate stepping stone in terms of implementation complexity, for applications that wish to have SMIL-compatible animation but do not need or want time containers.

This document describes an abstract feature and a concrete implementation of it for optimizing the transmission and/or wire format of SOAP messages. The concrete implementation relies on the XML-binary Optimized Packaging format for carrying SOAP messages.

SOAP Version 1.2 Part 0: Primer is a non-normative document intended to provide an easily understandable tutorial on the features of the SOAP Version 1.2 specifications. In particular, it describes the features through various usage scenarios, and is intended to complement the normative text contained in Part 1 and Part 2 of the SOAP 1.2 specifications.

SOAP Version 1.2 is a lightweight protocol intended for exchanging structured information in a decentralized, distributed environment. quot;Part 1: Messaging Frameworkquot; defines, using XML technologies, an extensible messaging framework containing a message construct that can be exchanged over a variety of underlying protocols.

SOAP Version 1.2 is a lightweight protocol intended for exchanging structured information in a decentralized, distributed environment. SOAP Version 1.2 Part 2: Adjuncts defines a set of adjuncts that may be used with SOAP Version 1.2 Part 1: Messaging Framework. This specification depends on SOAP Version 1.2 Part 1: Messaging Framework.

This document describes the semantics and serialization of a SOAP header block for carrying resource representations in SOAP messages.

This document draws on assertions found in the SOAP Version 1.2 specifications SOAP Part1, SOAP Part2, and provides a set of tests in order to show whether the assertions are implemented in a SOAP processor.

A SOAP 1.2 implementation that passes all of the tests specified in this document may claim to conform to the SOAP 1.2 Test Suite, 2003 06 24. It is incorrect to claim to be compliant with the SOAP Version 1.2 specifications merely by passing successfully all the tests provided in this test suite. It is also incorrect to claim that an implementation is non compliant with the SOAP Version 1.2 specifications based on its failure to pass one or more of the tests in this test suite.

This document defines syntax for representing grammars for use in speech recognition so that developers can specify the words and patterns of words to be listened for by a speech recognizer. The syntax of the grammar format is presented in two forms, an Augmented BNF Form and an XML Form. The specification makes the two representations mappable to allow automatic transformations between the two forms.

The Voice Browser Working Group has sought to develop standards to enable access to the Web using spoken interaction. The Speech Synthesis Markup Language Specification is one of these standards and is designed to provide a rich, XML-based markup language for assisting the generation of synthetic speech in Web and other applications. The essential role of the markup language is to provide authors of synthesizable content a standard way to control aspects of speech such as pronunciation, volume, pitch, rate, etc. across different synthesis-capable platforms.

This document specifies VoiceXML, the Voice Extensible Markup Language. VoiceXML is designed for creating audio dialogs that feature synthesized speech, digitized audio, recognition of spoken and DTMF key input, recording of spoken input, telephony, and mixed initiative conversations. Its major goal is to bring the advantages of Web-based development and content delivery to interactive voice response applications.

The World Wide Web uses relatively simple technologies with sufficient scalability, efficiency and utility that they have resulted in a remarkable information space of interrelated resources, growing across languages, cultures, and media. In an effort to preserve these properties of the information space as the technologies evolve, this architecture document discusses the core design components of the Web. They are identification of resources, representation of resource state, and the protocols that support the interaction between agents and resources in the space. We relate core design components, constraints, and good practices to the principles and properties they support.

This document specifies usage scenarios, goals and requirements for a web ontology language. An ontology formally defines a common set of terms that are used to describe and represent a domain. Ontologies can be used by automated tools to power advanced services such as more accurate web search, intelligent software agents and knowledge management.

XForms is an XML application that represents the next generation of forms for the Web. By splitting traditional XHTML forms into three partsXForms model, instance data, and user interfaceit separates presentation from content, allows reuse, gives strong typingreducing the number of round-trips to the server, as well as offering device independence and a reduced need for scripting.

XForms is not a free-standing document type, but is intended to be integrated into other markup languages, such as XHTML or SVG.

The XHML Basic document type includes the minimal set of modules required to be an XHTML host language document type, and in addition it includes images, forms, basic tables, and object support. It is designed for Web clients that do not support the full set of XHTML features; for example, Web clients such as mobile phones, PDAs, pagers, and settop boxes. The document type is rich enough for content authoring.

XHTML Basic is designed as a common base that may be extended. For example, an event module that is more generic than the traditional HTML 4 event system could be added or it could be extended by additional modules from XHTML Modularization such as the Scripting Module. The goal of XHTML Basic is to serve as a common language supported by various kinds of user agents.

The document type definition is implemented using XHTML modules as defined in quot;Modularization of XHTMLquot;

This Recommendation specifies an abstract modularization of XHTML and an implementation of the abstraction using XML Document Type Definitions (DTDs). This modularization provides a means for subsetting and extending XHTML, a feature needed for extending XHTML's reach onto emerging platforms.

This specification defines the Second Edition of XHTML 1.0, a reformulation of HTML 4 as an XML 1.0 application, and three DTDs corresponding to the ones defined by HTML 4. The semantics of the elements and their attributes are defined in the W3C Recommendation for HTML 4. These semantics provide the foundation for future extensibility of XHTML. Compatibility with existing HTML user agents is possible by following a small set of guidelines.

This Recommendation defines a new XHTML document type that is based upon the module framework and modules defined in Modularization of XHTML. The purpose of this document type is to serve as the basis for future extended XHTML 'family' document types, and to provide a consistent, forward-looking document type cleanly separated from the deprecated, legacy functionality of HTML 4 that was brought forward into the XHTML 1.0 document types. This document type is essentially a reformulation of XHTML 1.0 Strict using XHTML Modules. This means that many facilities available in other XHTML Family document types (e.g., XHTML Frames) are not available in this document type. These other facilities are available through modules defined in Modularization of XHTML, and document authors are free to define document types based upon XHTML 1.1 that use these facilities.

This document specifies a processing model and syntax for general purpose inclusion. Inclusion is accomplished by merging a number of XML information sets into a single composite infoset. Specification of the XML documents (infosets) to be merged and control over the merging process is expressed in XML-friendly syntax (elements, attributes, URI references).

This document specifies protocols for distributing and registering public keys, suitable for use in conjunction with the W3C Recommendations for XML Signature and XML Encryption. The XML Key Management Specification (XKMS) comprises two parts the XML Key Information Service Specification (X-KISS) and the XML Key Registration Service Specification (X-KRSS).

This document specifies protocol bindings with security characteristics for the XML Key Management Specification (XKMS).

This specification defines the XML Linking Language (XLink), which allows elements to be inserted into XML documents in order to create and describe links between resources. It uses XML syntax to create structures that can describe links similar to the simple unidirectional hyperlinks of today's HTML, as well as more sophisticated links.

Any XML document is part of a set of XML documents that are logically equivalent within an application context, but which vary in physical representation based on syntactic changes permitted by XML 1.0 and Namespaces in XML. This specification describes a method for generating a physical representation, the canonical form, of an XML document that accounts for the permissible changes. Except for limitations regarding a few unusual cases, if two documents have the same canonical form, then the two documents are logically equivalent within the given application context. Note that two documents may have differing canonical forms yet still be equivalent in a given context based on application-specific equivalence rules for which no generalized XML specification could account.

The XML Events module defined in this specification provides XML languages with the ability to uniformly integrate event listeners and associated event handlers with Document Object Model (DOM) Level 2 event interfaces. The result is to provide an interoperable way of associating behaviors with document-level markup.

Canonical XML specifies a standard serialization of XML that, when applied to a subdocument, includes the subdocument's ancestor context including all of the namespace declarations and attributes in the "xml:&qout; namespace. However, some applications require a method which, to the extent practical, excludes ancestor context from a canonicalized subdocument. For example, one might require a digital signature over an XML payload (subdocument) in an XML message that will not break when that subdocument is removed from its original message and/or inserted into a different context. This requirement is satisfied by Exclusive XML Canonicalization.

This specification provides a set of definitions for use in other specifications that need to refer to the information in an XML document.

XML namespaces provide a simple method for qualifying element and attribute names used in Extensible Markup Language documents by associating them with namespaces identified by URI references.

XML namespaces provide a simple method for qualifying element and attribute names used in Extensible Markup Language documents by associating them with namespaces identified by IRI references.

This document allows a style sheet to be associated with an XML document by including one or more processing instructions with a target of xml-stylesheet in the document's prolog.

The Extensible Markup Language (XML) is a subset of SGML that is completely described in this document. Its goal is to enable generic SGML to be served, received, and processed on the Web in the way that is now possible with HTML. XML has been designed for ease of implementation and for interoperability with both SGML and HTML.

This document proposes a facility, similar to that of HTML BASE, for defining base URIs for parts of XML documents.

This document specifies XML digital signature processing rules and syntax. XML Signatures provide integrity, message authentication, and/or signer authentication services for data of any type, whether located within the XML that includes the signature or elsewhere.

XML Signature recommends a standard means for specifying information content to be digitally signed and for representing the resulting digital signatures in XML. Some applications require the ability to specify a subset of a given XML document as the information content to be signed. The XML Signature specification meets this requirement with the XPath transform. However, this transform can be difficult to implement efficiently with existing technologies. This specification defines a new XML Signature transform to facilitate the development of efficient document subsetting implementations that interoperate under similar performance profiles.

This document specifies a process for encrypting data and representing the result in XML. The data may be arbitrary data (including an XML document), an XML element, or XML element content. The result of encrypting data is an XML Encryption element which contains or references the cipher data.

This document specifies an XML Signature &qout;decryption transform" that enables XML Signature applications to distinguish between those XML Encryption structures that were encrypted before signing (and must not be decrypted) and those that were encrypted after signing (and must be decrypted) for the signature to validate.

XML Schema Part 0: Primer is a non-normative document intended to provide an easily readable description of the XML Schema facilities, and is oriented towards quickly understanding how to create schemas using the XML Schema language. XML Schema Part 1: Structures and XML Schema Part 2: Datatypes provide the complete normative description of the XML Schema language. This primer describes the language features through numerous examples which are complemented by extensive references to the normative texts.

XML Schema: Structures specifies the XML Schema definition language, which offers facilities for describing the structure and constraining the contents of XML 1.0 documents, including those which exploit the XML Namespace facility. The schema language, which is itself represented in XML 1.0 and uses namespaces, substantially reconstructs and considerably extends the capabilities found in XML 1.0 document type definitions (DTDs). This specification depends on XML Schema Part 2: Datatypes.

XML Schema: Datatypes is part 2 of the specification of the XML Schema language. It defines facilities for defining datatypes to be used in XML Schemas as well as other XML specifications. The datatype language, which is itself represented in XML 1.0, provides a superset of the capabilities found in XML 1.0 document type definitions (DTDs) for specifying datatypes on elements and attributes.

This document defines the XML-binary Optimized Packaging (XOP) convention, a means of more efficiently serializing XML Infosets that have certain types of content.

XPath is a language for addressing parts of an XML document, designed to be used by both XSLT and XPointer.

The XPointer element() scheme is intended to be used with the XPointer Framework to allow basic addressing of XML elements.

This specification defines the XML Pointer Language (XPointer) Framework, an extensible system for XML addressing that underlies additional XPointer scheme specifications. The framework is intended to be used as a basis for fragment identifiers for any resource whose Internet media type is one of text/xml, application/xml, text/xml-external-parsed-entity, or application/xml-external-parsed-entity. Other XML-based media types are also encouraged to use this framework in defining their own fragment identifier languages.

The XPointer xmlns() scheme is intended to be used with the XPointer Framework to allow correct interpretation of namespace prefixes in pointers, for instance, namespace-qualified scheme names and namespace-qualified element or attribute names appearing within scheme data.

XML is a versatile markup language, capable of labeling the information content of diverse data sources including structured and semi-structured documents, relational databases, and object repositories. A query language that uses the structure of XML intelligently can express queries across all these kinds of data, whether physically stored in XML or viewed as XML via middleware. This specification describes a query language called XQuery, which is designed to be broadly applicable across many types of XML data sources.

This document presents an XML Syntax for XQuery 1.0

This specification defines the features and syntax for the Extensible Stylesheet Language (XSL), a language for expressing stylesheets. It consists of two parts:

• a language for transforming XML documents, and
• an XML vocabulary for specifying formatting semantics.

An XSL stylesheet specifies the presentation of a class of XML documents by describing how an instance of the class is transformed into an XML document that uses the formatting vocabulary.

This specification defines the syntax and semantics of XSLT, which is a language for transforming XML documents into other XML documents.


XSLT is also designed to be used independently of XSL. However, XSLT is not intended as a completely general-purpose XML transformation language. Rather it is designed primarily for the kinds of transformations that are needed when XSLT is used as part of XSL.