Participants to the workshop come with a very diverse set of background and expertise in relationship with Inclusive Design and XR. The Program Committee has assembled the following lexicon to help participants prepare for the discussions at the workshop - we do not expect all participants to be familiar with all the terms and jargon, but hope this can be used as a reference before, during and after the workshop to facilicate communication.

These definitions are informal, and should not be used or construed as formal W3C definitions.

3D engine
Software that provides high level APIs to simplify the development of 3D-rendered applications (e.g. games, XR experiences). Examples include Unity, Unreal Engine, and specifically for the Web BabylonJS and Three.js
3D model
An interconnected set of surfaces and geometric shapes in 3D that is used to represent 3D objects or entities. Formats that can be used to package these include glTF, FBX, USDZ.
3D scene graph
A declarative approach to describing a 3D environment as an interconnected collection of 3D objects and entities
3DOF (three degrees of freedom)
Refers to tracking of rotational motion only: pitch, yaw, and roll - in contrast with 6DOF
6DOF (six degrees of freedom)
Freedom to change position as forward/backward (surge), up/down (heave), left/right (sway) translation in three perpendicular axes, combined with changes in orientation through rotation about three perpendicular axes - in contrast with 3DOF
An open-source declarative framework to develop VR experiences on the Web in HTML
AG (Accessibility Guidelines) Working Group
W3C Working Group responsible for the standardization of accessibility guidelines, including the Web Content Accessibility Guidelines, the future Silver Accessibility Guidelines
Artificial Intelligence
A sounds format for spatialized audio that allows to describe audio sources in the 3 spatial dimensions
AOM (Accesibility Object Model)
A JavaScript API under incubation that enables developer to expose information to assistive technologies in an imperative manner
APA (Accessible Platform Architectures) Working Group
W3C Working Group that ensures W3C specifications provide support for accessibility to people with disabilities
Application Programing Interface - a well-defined set of code instructions developers can use to trigger well-defined outcomes
AR (Augmented Reality)
Overlaying virtual artefacts on top of a real-world environment (e.g. through a headset or in a "magic window" approach on a phone)
AR headset
A headset that allows to visualize AR artefacts via a seethrough screen in front of the user's eyes - e.g. Hololens or Magic Leap One
The SDK provided on Android to develop AR experiences
The SDK provided on iOS to develop AR experiences
ARIA (Accessible Rich Internet Applications) is a suite of technologies that provides declarative markup to help make Web content accessible via assistive technologies
Assistive Technologies (AT)
Artefacts that enhance learning, working, and daily living for persons with disabilities
American Sign Language
ATAG (Authoring Tools Accessibility Guidelines)
W3C guidelines for designing web content authoring tools that are both more accessible to authors with disabilities and designed to enable, support, and promote the production of more accessible web content by all authors.
The graphical representation of the user or the user's alter ego or character.
an open-source 3D Engine for the Web
canvas element
An HTML element which gets combined with an imperative JavaScript API to draw any type of graphical content. It is used in the Immersive Web to draw 3D content via WebGL (and probably WebGPU in the future). Work to make content drawn with this approach in 2D accessible involved providing hit testing support.
Cardboard | Google Cardboard
A cheap mobile VR headset where a user would put their phone to enable basic VR experiences
Community Group
CSS (Cascading Style Sheets)
Daydream | Google Daydream
A platform for Android phones to enable them as basis for mobile VR headsets
declarative (programming language)
An approach where the developer declares their intent with high level semantics (e.g. via a markup language) and leaves it to the computer to represent that intent to the end-user - by opposition to imperative
Deaf and hard of hearing
DOM (Document Object Model)
A JavaScript API that allows developers to modify dynamically the content of a Web page
a proprietary 3D model format
The 3D space covered by the field of view in a headset
Gamepad API
A JavaScript API that enables to use gamepads, and - via WebXR - XR controllers as well, in Web applications
gaze interaction
Gaze-based interactions rely on the user rotating their heads and looking at objects to interact with them.
GearVR | Samsung GearVR
A mobile VR headset where a user would put their phone to enable basic VR experiences
a standards 3D model format, developed by the Khronos Group
interactions based on the sense of touch (e.g. touch screen, vibrations)
Hit testing [canvas]
Accommodation for the canvas element to make imperative user interfaces built with it accessible by exposing them to assistive technologies
Hit testing [real-world]
Ability to detect surfaces or objects in the real-world to enable positioning AR artefacts in it
Hololens | Microsoft Hololens
An AR headset by Microsoft
the declarative markup language with which most pages are developed
Image recognition
AI driven recognition and understanding of the content of images or other graphical material.
Immersive Web
The Immersive Web is the project in W3C, carried by the Immersive Web Working Group and Immersive Web Community Group, to make Web browsers a platform to develop and distribute AR & VR experiences to any device using Web technologies. The lead component of that project is the WebXR API.
Immersive Web Community Group
A Community Group in W3C that incubates technologies for future standardization to enable the Immersive Web vision
Immersive Web Working Group
W3C Working Group that standardizes the technical components to enable the Immersive Web vision, currently focused on WebXR
imperative (programming language)
An approach where the developer gives specific instructions (via APIs) to the computer in how the content is rendered and how user input is handled - by opposition to declarative
incubation [standards]
Informal process through which technologies can be built and experimented with in a fast iteration approach (typically in a Community Group) before going through the formal standardization process (in W3C, in a Working Group)
Inclusive Design
designing for the needs of people with permanent, temporary, situational, or changing disabilities
A programming language that can be used for imperative developments in Web browsers via the JavaScript APIs they provide
JavaScript API
An API for use in browsers that enable developers to write JavaScript code to achieve certain effects. DOM, WebGL, WebXR, WebGPU, AOM are examples of APIs that have been standardized or are being standardized to enable new capabilities in Web browsers.
Khronos Group
A standards organization for 3D graphics, Virtual and Augmented Reality, Parallel Computing, Neural Networks, and Vision Processing. The Khronos Group standardized WebGL, OpenXR, glTF among other things.
Magic Leap One | Magic Leap
An AR headset by Magic Leap
magic window
Approach to render VR or AR content where a mobile phone screen is used as if it was a window on the virtual world or the augmented world - by opposition to immersive VR
Declarative code that allows to structure, annotate and enrich content - HTML is a markup language that serves as the basis of most Web pages
Mixed Reality (MR)
Sometimes used to refer to AR experiences that are more integrated in the real world; also the name of the XR platform in Windows
mobile VR headset
Headset for immersive VR that can be used independently from a computer (e.g. GearVR, Daydream, Cardboard)
native applications
Applications developed using SDKs specific to an OS or a platform - by opposition to Web applications
A standard cross-platform API for native development of VR & AR applications
Quest | Oculus Quest
a mobile VR headset by Oculus
Recommendation (W3C)
The name W3C gives to its finalized standards. The Process through which they are produced is known as the Recommendation track.
Rift | Oculus Rift
a tethered VR headset by Oculus
RQTF (WAI Research Question Task Force)
A task force of the W3C APA Working Group focused on addressing accessibility knowledge gaps and barriers in emerging and future web technologies
screen magnifier
Software that magnifies a small portion of on-screen content multiple times, allowing it to take up all the available screen space.
screen reader
Software that translates on-screen content into synthetic speech or electronic braille.
SDK (Software Development Kit)
A set of tools and APIs that enable developers to build applications for a certain platform or product
Silver guidelines
The next generation of accessibility guidelines envisioned by the W3C Accessibility Guidelines Working Group to replace WCAG and other guidelines
Spatialized audio
Audio content that is rendered to be perceived as coming from different positions in the 3D space
speech recognition
Software that enables technology and interaction to be controlled with voice commands.
tag [HTML]
A piece of markup that developers use to convey a well-defined semantic
tethered VR headset
Headset for immersive VR that is used in combination with (and often plugged into) a computer (e.g. Oculus Rift, Windows Mixed Reality headsets, HTC Vive)
an open-source 3D Engine for the Web
UAAG (User Agent Accessibility Guidelines)
Guidelines that explain how to make user agents ( accessible to people with disabilities. User agents include browsers, browser extensions, media players, readers and other applications that render web content
A commercial 3D Engine developed by Unity Technologies, available both in native and Web context
Unreal Engine
A commercial 3D Engine developed by Epic Games, available both in native and Web contexts
user agent
Software that acts on behalf of the user when interacting with content or protocols; often used as a synonym to Web browser in the W3C context
a proprietary 3D model format
TTML (Timed Text Markup Language)
A declarative markup format to describe timed text, such as captions or audio descriptions. The format is not currently natively interpreted by Web browsers. See also WebVTT.
Vive | HTC Vive
a tethered VR headset by HTC
voice assistant
Software or hardware that that uses voice as its primary mode of interaction.
VR (Virtual Reality)
Computer-generated environments in which the user can evolve in all dimensions of space; can be either through a VR headset or through a magic window approach
VR headset
Headset that fills (most of) the user field of view and make them feel completely immersed in the virtual environment - by opposition to magic window mode of VR
Web Accessibility Initiative, a W3C initiative that makes the Web accessible through the development of standards and support materials to help understand and implement accessibility.
WCAG (Web Content Accessibility Guidelines)
Guidelines standardized in W3C to help make Web content more accessible. Currently at version 2.1, with plans for a version 2.2, and future plans for a more radical evolution known as Silver
Web applications
Applications developed with Web technologies (HTML, CSS, JavaScript APIs) that run in Web browsers - by opposition to native applications
Web Assembly
Technology developed in W3C available in recent Web browsers that enable to run code developed in other programming languages than JavaScript, with very high performance
Web Audio API
A JavaScript API developed in W3C that allows to render audio in Web browsers
A JavaScript API developed in Khronos that enables graphical rendering of 3D content in Web browsers via the canvas element. WebGPU may provide a more powerful alternative in the future.
A JavaScript API developed in incubation in a Community Group in W3C, similar in scope to WebGL (incl. enabling 3D graphics) but with more modern and Web-friendly characteristics
An experimental and now deprecated JavaScript API that was available in browsers to render VR experiences via Web browsers. Replaced by WebXR
A declarative format (inspired from SRT) to describe timed text, such as captions or audio descriptions. Natively supported by recent Web browsers.
A JavaScript API being standardized by the W3C Immersive Web Working Group that provides access to AR & VR devices from Web browsers and the necessary hooks to render 3D content (e.g. via WebGL, Web Audio and the gamepad API). Replaces WebVR and constitutes the current main component of the Immersive Web project.
Working Group
In W3C, a formally chartered group that follows the W3C Process and its Recommendation track to develop standards for the Web.
XR (extended reality)
An umbrella term that encompasses Augmented Reality (AR), Mixed Reality (MR) and Virtual Reality (VR)