Firefox 26 was released on December 10, 2013. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Want to help document Firefox 26? See the list of bugs that need to be written about and pitch in!
Changes for Web developers
text-decoration-lineproperty, still prefixed, now considers
'blink'as a valid value, though it doesn't blink the content at all (bug 812995).
- The non-standard
-moz-text-blinkproperty has been removed (bug 812995).
- Support for the
image-orientationproperty, in its CSS Images & Values Level 4 version, that is with the
from-imagekeyword and EXIF support, has been added (bug 825771).
- Experimental support for
position: stickyhas been implemented and can be enabled by pref
text-alignproperty now applies to the
::-moz-placeholderpseudo-element (bug 915551).
HTMLSelectElement.selectedOptionsproperty has been implemented (bug 596681).
- In the
<input>element of type
heightproperties now return
<fieldset>element is now invalid, and can be styled using the
:invalidpseudo-class, when one of the elements it contains is invalid (bug 717181).
EcmaScript 6 (Harmony) implementation continues!
- The ECMAScript 6 compliant syntax for Generators (yield) has been implemented (bug 666399).
- New mathematical methods have been implemented on
- The reserved words cannot be used for function names:such a usage now throws a
- Make the last argument (doctype) to
DOMImplementation.createDocumentoptional (bug 909859).
- Implement the new
element.classListspecification which permits adding/removing several classes with one call (bug 814014).
URL()constructor have been implemented on the
URLinterface (bug 887364).
- The properties
URLUtils.usernameare now available to all interfaces implementing
URLinterface is now accessible from Web Workers (bug 887364).
- IndexedDB can now be used as a "optimistic" storage area so it doesn't require any prompts and data is stored in a pool with LRU eviction policy, in short temporary storage (bug 785884).
- Path of the persistent storage has been changed from
<profile>/storage/persistent(on b2g from
Screen.lockOrientation()method now support the
defaultvalue, mapping to
landscape-primary, depending of the device (bug 908058).
Eventconstructors can be used in Web workers (bug 910910).
- Trying to set the
Document.domainproperty on a page embedded in an
sandboxattribute now throws a security error (bug 907892).
MessageEventinterface has been updated to comply with the latest spec. The
initMessageEventmethod has been removed while the interface has now a constructor (bug 848294).
- The HTML5
MessageChannelAPI has been implemented, behind the
dom.messageChannel.enabledpreference (bug 677638).
- Support for
VTTCue, behind the
media.webvtt.enabledpreference, like for all WebVTT-related implementations, has been added (bug 868509).
- Inconsistent renderings of
<msubsup>have been unified and the error handling of these elements has been improved (bug 827713).
- The inclusion of SVG glyphs inside OpenType, SVG-in-OpenType, has been updated to match the current version of the specification (bug 906521).
SVGElement.ownerSVGElement()method doesn't throw anymore (bug 835048).
- The Inspector is now remotable (bug 805526).
- The web console text can be selected,
::afternow inspectable, debugger and responsive design features are planned for this release. (https://hacks.mozilla.org/2013/09/new-features-in-the-firefox-developer-tools-episode-26/)
- Firefox 25 for developers
- Firefox 24 for developers
- 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
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- Firefox 13 for developers
- Firefox 12 for developers
- Firefox 11 for developers
- Firefox 10 for developers
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- 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