1. Custom protocol handling

    Method of allowing a webpage to handle a given protocol using `navigator.registerProtocolHandler`. This allows certain URLs to be opened by a given web application, for example `mailto:` addresses can be opened by a webmail client.

  2. requestIdleCallback

    API allowing the execution of JavaScript to be queued to run in idle browser time, either at the end of a frame or when the user is inactive. Also covers support for `cancelIdleCallback`. The API has similarities with `requestAnimationFrame`.

  3. unhandledrejection/rejectionhandled events

    The `unhandledrejection` event is fired when a Promise is rejected but there is no rejection handler to deal with the rejection. The `rejectionhandled` event is fired when a Promise is rejected, and after the rejection is handled by the promise's rejection handling code.

  4. htmldlistelement api

  5. htmldlistelement api: compact

  6. idledeadline api

  7. idledeadline api: didtimeout

  8. idledeadline api: timeremaining

  9. idledetector api

  10. idledetector api: `change` event

  11. idledetector api: `idledetector()` constructor

  12. idledetector api: `requestpermission()` static method

  13. idledetector api: screenstate

  14. idledetector api: start

  15. idledetector api: userstate

  16. keyboardlayoutmap api

  17. keyboardlayoutmap api: [symbol.iterator]

  18. keyboardlayoutmap api: entries

  19. keyboardlayoutmap api: foreach

  20. keyboardlayoutmap api: get

  21. keyboardlayoutmap api: has

  22. keyboardlayoutmap api: keys

  23. keyboardlayoutmap api: size

  24. keyboardlayoutmap api: values

  25. svganimatedlength api

  26. svganimatedlengthlist api

  27. svganimatedlengthlist api: animval

  28. svganimatedlengthlist api: baseval

  29. svganimatedlength api: animval

  30. svganimatedlength api: baseval

  31. xrquadlayer api

  32. xrquadlayer api: height

  33. xrquadlayer api: `redraw` event

  34. xrquadlayer api: space

  35. xrquadlayer api: transform

  36. xrquadlayer api: width

  37. html element: dl

  38. javascript built-in: array: findlast

  39. javascript built-in: array: findlastindex

  40. javascript built-in: intl: collator: supportedlocalesof

  41. javascript built-in: intl: segmenter: supportedlocalesof

  42. javascript built-in: typedarray: findlast

  43. javascript built-in: typedarray: findlastindex