1. :indeterminate CSS pseudo-class

    The `:indeterminate` pseudo-class matches indeterminate checkboxes, indeterminate `<progress>` bars, and radio buttons with no checked button in their radio button group.

  2. CSS writing-mode property

    Property to define whether lines of text are laid out horizontally or vertically and the direction in which blocks progress.

  3. Decorators

    ECMAScript Decorators are an in-progress proposal for extending JavaScript classes. Decorators use a special syntax, prefixed with an `@` symbol and placed immediately before the code being extended.

  4. progress element

    Method of indicating a progress state.

  5. Add to home screen (A2HS)

    The ability for a user to "install" a website and use it as if it was a natively installed app. To enable this behaviour, a website must serve a valid Web App Manifest and load it's assets through a [Service Worker](https://caniuse.com/#feat=serviceworkers).

  6. XMLHttpRequest advanced features

    Adds more functionality to XHR (aka AJAX) requests like file uploads, transfer progress information and the ability to send form data. Previously known as [XMLHttpRequest Level 2](https://www.w3.org/TR/2012/WD-XMLHttpRequest-20120117/), these features now appear simply in the XMLHttpRequest spec.

  7. applicationcache api: `progress` event

  8. backgroundfetchregistration api: `progress` event

  9. filereader api: `progress` event

  10. htmlmediaelement api: `progress` event

  11. htmlprogresselement api

  12. htmlprogresselement api: labels

  13. htmlprogresselement api: max

  14. htmlprogresselement api: position

  15. htmlprogresselement api: value

  16. progressevent api

  17. progressevent api: lengthcomputable

  18. progressevent api: loaded

  19. progressevent api: `progressevent()` constructor

  20. progressevent api: total

  21. xmlhttprequestupload api: `progress` event

  22. xmlhttprequest api: `progress` event

  23. css property: appearance: `<compat-auto>` (compatibility values `searchfield`, `textarea`, `push-button`, `slider-horizontal`, `checkbox`, `radio`, `square-button`, `menulist`, `listbox`, `meter`, `progress-bar`, `button`)

  24. css property: cursor: `progress`

  25. css selector: `::-moz-range-progress`

  26. css selector: `::-webkit-progress-bar`

  27. css selector: `::-webkit-progress-inner-element`

  28. css selector: `::-webkit-progress-value`

  29. css selector: `:indeterminate`: applies to `<progress>` elements

  30. html element: progress: max

  31. html element: progress: value