WAI defines guidelines for how to make the Web content accessible to people with disabilities.

The Web Accessibility Initiative is working for the "Web accessibility for all" through technology, guidelines, tools, education, research, and development projects.

The W3C WAI Recommendations  

MathML describes an XML standard for describing the mathematical notation.

The goal of MathML is to enable mathematics to be served, received, and processed on the Web, just as the HTML has enabled this functionality for text.

The W3C MathML Recommendations  

SVG is a language for describing two-dimensional graphics in the XML.

SVG allows for the three types of graphic objects: vector graphic shapes, images and text.

The feature set includes the nested transformations, clipping paths, alpha masks, filter effects, template objects and extensibility.

The W3C SVG 1.1 Recommendation

The W3C SVG 1.2 Working Draft

InkML is an XML data format for representing the digital ink data that is input with an electronic pen or stylus as part of a multimodal system.

The W3C InkML Working Draft

The W3C Internationalization Activity has the goal of proposing and coordinating any technique, conventions, guidelines and activities within the W3C and together with other organizations that allow and make it easy to use W3C technology worldwide, with different languages, scripts, and cultures.

W3C Internationalization Activity

W3C voice browser activity is allabout expanding the Web to allow people to interact via spoken commands and synthetic speech.

Voice Extensible Markup Language (VoiceXML)

Speech Synthesis Markup Language

Speech Recognition Grammar Specification

Voice Browser Call Control (CCXML)

W3C Home Page