Firefox 24 for developers
=========================

Changes for Web developers
--------------------------

### CSS

* The two values `-moz-zoom-in` and `-moz-zoom-out` of the `cursor` property have been unprefixed to `zoom-in` and `zoom-out` (Firefox bug 772153).
* To match the specification, the keywords `not`, `only`, `and`, and `or` cannot be used as media types anymore (Firefox bug 757554).
### HTML

* The `<track>` element has been implemented behind the `media.webvtt.enabled` preference, and is disabled by default. (Firefox bug 833385).
### JavaScript

* Arrow functions are no longer automatically in strict mode unless explicitly requested with `"use strict"` (Firefox bug 852762).
* The `String.prototype.repeat` JS method has been implemented (Firefox bug 815431).
* The `Set.prototype.values()`, `Set.prototype.keys()` and `Set.prototype.entries()` methods on `Set` objects have been implemented (Firefox bug 869996).
### DOM

* Support for the `Range()` constructor has been added (Firefox bug 868999).
* Support for the `Text()` constructor has been added (Firefox bug 869000).
* Support for the `Comment()` constructor has been added (Firefox bug 869006).
* Support for the `DocumentFragment()` constructor has been added (Firefox bug 869002).
* The `FocusEvent` interface has been implemented (Firefox bug 855741).
* Support for the `ChildNode.remove()` method has been added (Firefox bug 856629).
* The WebVTT interfaces related to the `<track>` element, `HTMLTrackElement`, `TextTrack`, `TextTrackCue`, `TextTrackList`, and `TextTrackCueList` have been implemented behind the `media.webvtt.enabled` property, defaulting to `false` (Firefox bug 833385).
* The `Gamepad` interface, and `Navigator.getGamepads` have been implemented behind the `dom.gamepad.enabled` property, defaulting to `false` (Firefox bug 690935).
* On desktop Firefox only, `HTMLCanvasElement.getContext()` can now take the `webgl` value, in addition to `experimental-webgl` (Firefox bug 870232).
* The non-standard method `mozLoadFrom()` of `HTMLMediaElement` has been removed (Firefox bug 877135).
### Developer Tools

* The Network inspector now lets you filter by content type (CSS/image/font etc.) and see the relevant size and load times.
* The Devtools options panel to the left lets you disable/enable JavaScript temporarily.
* Extension developers may use the new Browser Console for Chrome-level scripts (Replaces Error Console).
* The source map syntax has been changed to use `//#` instead of `//@` (Firefox bug 870361).
### MathML

* The `dir` attribute for controlling directionality of formulas on e.g. `<math>` or `<mrow>` elements is now equivalent to using the `direction` CSS property.
* The equal sign ("=") is now stretchable.
* The "`updiagonalarrow`" value for the `notation` attribute on `<menclose>` elements has been added.
Changes for add-on and Mozilla developers
-----------------------------------------

* Doc Shells have now the `allowMedia` attribute to disable media playing (Firefox bug 759964).
* Sherlock search plugins in the application directory or profile won't be loaded anymore (Firefox bug 862143).
See also
--------

* Firefox 24 Aurora Notes
Older versions
--------------

* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers