- Accessibility: All specifications aiming at making the Web accessible to people with disabilities
- Browser: Specifications for Web browsers and other interactive user agents
- CSS: How documents are presented on screens using CSS
- Data: Specifications to facilitate the creation, exchange, and usage of semantically rich data on the Web
- Digital Publishing: Specifications dealing with digital publishing like electronic books or journals, and based on W3C technologies such as HTML, SVG, CSS, or MathML.
- DOM: Specifications describing the Document Object Model (DOM)
- Graphics: Specifications dealing with graphical content (image formats, web fonts, canvas, etc)
- HTML: Defines the HyperText Markup Language (HTML) format and its extensions
- HTTP: client-server protocol allowing resources fetching such as HTML.
- i18n: How to use Web Technologies with different languages, scripts and culture
- Media: Specificaitons related to audio, video and captions and other Web Media related items
- Performance: Specifications to measure and improve aspects of application performance of user agent features and API
- Privacy: Specifications aiming at improving support for user privacy on the Web
- Protocol: Defining the different protocols used on the Web
- Security: Provides technical and policy mechanisms to improve security and enable secure cross-site communications for applications on the Web
- Web API: Specifications providing APIs to allow Web applications to access specific features or data
- Web Fonts: How fonts are specified, used for presenting text, and automatically downloaded on demand
- WoT: Provides interoperability across Internet of Things (IoT) Platforms and application domains
- XML: Specifications defining the Extensible Markup Language (XML) and its extensions