The background-attachment CSS property sets whether an element's background image or gradient moves as the element scrolls.

The path() CSS shape function creates a shape for clip-path, shape-outside, and the SVG attribute d.

The reversed() CSS function for counter-reset creates a counter that counts down.

The navigator.deviceMemory property is the approximate amount of device memory, in gigabytes.

The optional colorSpace parameter of a 2D canvas's getContext() method chooses the color representation, such as "srgb" or "display-p3".

The cursor CSS property styles the pointer, allowing you to provide hints to the user on how to interact with the hovered element.

The protocol_handlers web app manifest member registers an installed web app as a handler for a specific protocol. When a user follows a link with the specified protocol, the installed app opens the link.

The EyeDropper API opens an eyedropper tool, a color picker that allows users to select a color from their screen.

The image-rendering: smooth CSS declaration scales images while retaining a gradual color blending that is useful for photos.

The Profiler API records data about the execution of a page, which you can send to a server for later analysis. Also known as self-profiling.

The navigator.virtualKeyboard API inspects and controls on-screen virtual keyboards. You can use it to programmatically hide or show a virtual keyboard or respond to the keyboard disappearing or appearing.

The navigator.ink API uses the system compositor to draw to a <canvas> element ahead of pointer events, reducing the delay between moving a stylus or cursor and a pen stroke appearing on screen.

The EXT_frag_depth extension for WebGL 1.0 and 2.0 contexts adds setting the depth value of a fragment from within the fragment shader.

The WEBGL_draw_buffers extension for WebGL 1.0 contexts enables a fragment shader to write to several textures, which is useful for deferred shading, for example.

The WEBGL_multi_draw extension for WebGL 1.0 and 2.0 contexts renders more than one primitive with a single function call.

The optional desynchronized parameter of a canvas's getContext() method permits the browser to draw a 2D canvas independently of the event loop. This can reduce drawing latency.

The name="theme-color" attribute for the <meta> HTML element suggests a color that the browser can use to customize the display of the page or the browser user interface.

The navigator.mediaSession API integrates with platform UI for media playback. It can be used to set metadata such as title and artwork, and to handle user actions like playing, pausing, or seeking.

The OVR_multiview2 extension for WebGL 2.0 contexts renders into multiple views simultaneously. This especially useful for virtual reality (VR) and WebXR.

The Sec-Fetch-Dest, Sec-Fetch-Mode, Sec-Fetch-Site, and Sec-Fetch-User HTTP headers provide extra information about the way a request was made, to help servers reject certain kinds of malicious requests.

The ascent-override, descent-override, and line-gap-override descriptors adjust the display of a font declared in an @font-face statement. This can help make fallback fonts look the same size.

The Accelerometer, LinearAccelerationSensor and GravitySensor APIs read the acceleration applied to a device in three dimensions, either including the effect of gravity, without its effect, or only its effect, respectively.

The Request.formData() and Response.formData() methods read a request or response body and return a FormData promise. You can use it to access the fields of a form submission.

An AudioListener object represents the virtual position and orientation of a person relative to sound sources, to spatialize audio in a Web Audio context.

The window.performance.timing and window.performance.navigation APIs report performance timing information for events that occur during the loading and use of the current page.

The EXT_float_blend extension for WebGL 1.0 and 2.0 contexts adds 32-bit floating-point components to blending and draw buffers.

The KHR_parallel_shader_compile extension for WebGL 1.0 and 2.0 contexts checks the status of shader compilation without blocking the runtime.

The WEBGL_compressed_texture_s3tc_srgb extension for WebGL 1.0 and 2.0 contexts adds S3TC compressed texture formats for the sRGB colorspace to compressedTexImage2D() and compressedTexSubImage2D().

The WebVTT cue alignment settings control which part of the cue is aligned with the given line and position. Cue alignment is set using line and position settings in WebVTT files or the lineAlign and positionAlign properties of VTTCue using JavaScript.

WebVTT regions set the areas of the video where captions or subtitles should be rendered, such as placing roll-up captions used for live captions.