1. classList (DOMTokenList)

    Method of easily manipulating classes on elements, using the `DOMTokenList` object.

  2. Basic console logging functions

    Method of outputting data to the browser's console, intended for development purposes.

  3. Ogg Vorbis audio format

    Vorbis is a free and open source audio format, most commonly used with the Ogg container.

  4. Ogg/Theora video format

    Free lossy video compression format.

  5. Proxy object

    The Proxy object allows custom behavior to be defined for fundamental operations. Useful for logging, profiling, object visualization, etc.

  6. CSS3 3D Transforms

    Method of transforming an element in the third dimension using the `transform` property. Includes support for the `perspective` property to set the perspective in z-space and the `backface-visibility` property to toggle display of the reverse side of a 3D-transformed element.

  7. domtokenlist api: toggle

  8. domtokenlist api: toggle: `force` parameter

  9. element api: toggleattribute

  10. htmldetailselement api: `toggle` event