RDFa Core is a specification for attributes to express structured data in any markup language. The embedded data already available in the markup language (e.g., XHTML) is reused by the RDFa markup, so that publishers don't need to repeat significant data in the document content.

RDFa Core 1.1 defines attributes and syntax for embedding semantic markup in Host Languages. This document defines one such Host Language. This language is a superset of XHTML 1.1, integrating the attributes as defined in RDFa Core 1.1.

RDFa Lite is a small subset of RDFa consisting of a few attributes that may be applied to most simple to moderate structured data markup tasks. While it is not a complete solution for advanced markup tasks, it does provide a good entry point for beginners.

XHTML Basic 1.1 defines a profile of XHTML designed for small devices.

XHTML 1.1 redefines XHTML 1.0 based on a modular design, with support for Ruby Annotation.

XHTML Print defines a profile of XHTML designed for printing from mobile devices to low-cost printers.

DOM Level 2 HTML defines a programming interface to access and update the content and structure of HTML and XHTML documents.

XHTML 1.0 is a reformulation of HTML 4 as an XML language.

"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.

HTML microdata is an extension to HTML used to embed machine-readable data into HTML documents. Whereas the microdata specification describes a means of markup, the output format is JSON. This specification describes processing rules that may be used to extract RDF [RDF-CONCEPTS] from an HTML document containing microdata.

RDFa [RDFA-CORE] enables authors to publish structured information that is both human- and machine-readable. Concepts that have traditionally been difficult for machines to detect, like people, places, events, music, movies, and recipes, are now easily marked up in Web documents. While publishing this data is vital to the growth of Linked Data, using the information to improve the collective utility of the Web for humankind is the true goal. To accomplish this goal, it must be simple for Web developers to extract and utilize structured information from a Web document. This document details such a mechanism; an RDFa Application Programming Interface (RDFa API) that allows simple extraction and usage of structured information from a Web document.

HTML and RDFa (Resource Description Framework in Attributes) provides a set of markup attributes to augment visual information on the Web with machine-readable hints. In this Primer, we show how to express data using RDFa in HTML, and in particular how to mark up existing human-readable Web page content to express machine-readable data.

Microformats, RDFa and microdata all enable consumers to extract data from HTML pages. This data may be embedded within enhanced search engine results, exposed to users through browser extensions, aggregated across websites or used by scripts running within those HTML pages.

This document is the report of the TAG Task Force established to explore how interoperability between HTML and XML could be improved. It describes several use cases that the Task Force considered relevant and proposed resolutions to those cases.

The XHTML Access module defines an element that, when used in conjunction with other XHTML modules in XHTML Family Markup Languages, enables a more robust accessibility model than is presently possible.

The HLink module defined in this specification provides XHTML Family Members with the ability to specify which attributes of elements represent Hyperlinks, and how those hyperlinks should be traversed, and extends XLink use to a wider class of languages than those restricted to the syntactic style allowed by XLink.

XFrames is an XML application for composing documents together, replacing HTML Frames. By being a separate application from XHTML, it allows content negotiation to determine if the user agent accepts frames; by encoding the 'population' of frames in the URI, it allows framesets to be bookmarked.

XHTML Media Types recapitulates which media types can and should be used with the different flavors of XHTML, and under what conditions.

Offline Web Applications highlights the features in HTML 5 that address the challenge of building Web applications that work while offline.

This document describes XML Schemas for XHTML 1.0.

This specification defines HTML form enhancements that provide access to the audio, image and video capture capabilities of the device.

This specification defines the 5th major revision of the core language of the World Wide Web: the Hypertext Markup Language (HTML). In this version, new features are introduced to help Web application authors, new elements are introduced based on research into prevailing authoring practices, and special attention has been given to defining clear conformance criteria for user agents in an effort to improve interoperability.

Defines the flat cartesian surface that is the context for the canvas element (for drawing).

This document defines data categories and their implementation as a set of elements and attributes called the Internationalization Tag Set (ITS) 2.0. ITS 2.0 is the successor of ITS 1.0; it is designed to foster the creation of multilingual Web content, focusing on HTML5, XML based formats in general, and to leverage localization workflows based on the XML Localization Interchange File Format (XLIFF). In addition to HTML5 and XML, algorithms to convert ITS attributes to RDFa and NIF are provided.

This specification defines a longdesc attribute to link extended descriptions with images in HTML5-based content.

An overview of usage scenarios and implementations demonstrating applications of the Internationalization Tag Set (ITS) 2.0. The usage scenarios are ranging from simple machine translation or human translation quality check to training for machine translation systems or automatic text analyis.

When authors adapt their sites for high-resolution displays, they often need to be able to use different assets representing the same image. We address this need for adaptive, bitmapped content images by adding a srcset attribute to the img element.

This document adds an additional public identifier that should be recognised by XHTML user agents and cause the HTML character entity definitions to be loaded.

The picture element is an image container whose source content is determined by one or more CSS media queries.

This document captures the use cases and requirements for standardizing a solution for responsive images.

This document is a practical guide for developers on how to add accessibility information to HTML elements using ARIA, a markup mechanism for making Web content and Web applications more accessible to people with disabilities.

This specification defines the 5th major version, first minor revision of the core language of the World Wide Web: the Hypertext Markup Language (HTML). In this version, new features continue to be introduced to help Web application authors, new elements continue to be introduced based on research into prevailing authoring practices, and special attention continues to be given to defining clear conformance criteria for user agents in an effort to improve interoperability.

This specification defines the 2D Context, Level 2 for the HTML canvas element. The 2D Context provides objects, methods, and properties to draw and manipulate graphics on a canvas drawing surface.

This specification is an extension to the HTML5 specification. It defines an element to be used for the identification of the main content area of a document. The main element formalises the common practice of identification of the main content section of a document using the id values such as 'content' and 'main'. It also defines an HTML element that embodies the semantics and function of the WAI-ARIA landmark role=main.

HTML 5 defines the fifth major revision of the core language of the World Wide Web, HTML. "HTML 5 differences from HTML 4" describes the differences between HTML 4 and HTML 5 and provides some of the rationale for the changes. This document may not provide accurate information as the HTML 5 specification is still actively in development. When in doubt, always check the HTML 5 specification itself. [HTML5]

This document describes the HTML markup language and provides details to help producers of HTML content create documents that conform to the language. It is not the normative specification but intended for authors.

This specification defines a mechanism for machine-readable data to be embedded in HTML documents in an easy-to-write manner, with an unambiguous parsing model. It is compatible with numerous other data formats including RDF and JSON.

A document that uses polyglot markup is document that is a stream of bytes that parses into identical document trees (with the exception of the xmlns attribute on the root element) when processed as HTML and when processed as XML. Polyglot markup that meets a well defined set of constraints is interpreted as compatible, regardless of whether they are processed as HTML or as XHTML, per the HTML5 specification.

This document contains author conformance requirements for use of the alt attribute in HTML5 and best practice guidance for authors of HTML documents on providing text alternatives for images.

This document maps HTML elements and attributes to accessibility API roles, states and properties on a variety of platforms.

This document is a strict subset of the HTML5 specification that omits user-agent (UA) implementation details. It is targeted toward Web authors and others who are not UA implementors and who want a view of the HTML specification that focuses more precisely on details relevant to using the HTML language to create Web documents and Web applications.

This document looks at a number of use cases involving ruby, and examines the pros and cons of a number of alternative approaches for meeting those use cases using the current HTML5 model, the XHTML Ruby Annotation model, and two other models. The aim is to clarify which use cases are supported by the existing markup models (HTML5 or XHTML), and where they are not, provide suggestions about how the markup model could be adapted to support those use cases. Implementers and standards developers can then take this background information and the suggestions in this document to specify and implement a comprehensive markup model for ruby in HTML5.

Aggregates requirements of a user with disabilities with respect to audio and video on the Web, providing background on user needs, alternative content technologies, and their application on the Web.

XForms for HTML provides a set of attributes and script methods that can be used by the tags or elements of an HTML or XHTML web page to simplify the integration of data-intensive interactive processing capabilities from XForms.

HTML 5 Publication Notes is a companion document to the HTML 5 specification that gives more context about a given version of the drafts.

An XHTML+MathML+SVG profile is a profile that combines XHTML 1.1 [XHTML11], MathML 2.0 [MathML2] and SVG 1.1 [SVG11] together. This profile enables mixing XHTML, MathML and SVG in the same document using XML namespaces [XMLNS] mechanism, while allowing validation of such a mixed-namespace document. An XHTML 1.1 + MathML 2.0 + SVG 1.1 DTD driver is provided. An XHTML version of this document is conforming to this DTD.

This was used to document the HTML Working Group roadmap at some point of its history.