Firefox 44 for developers

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Firefox 44 was released on January 26, 2016. 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.

Changes for Web developers

Developer tools

Highlights:

All devtools bugs fixed between Firefox 43 and Firefox 44.

HTML

CSS

  • position: fixed; now always creates a new stacking context (bug 1179288).
  • The support of unicode-range has been enabled by default (bug 1119062).
  • Our experimental implementation of CSS Writing Modes has been updated to reflect the latest specification:
  • The non-standard properties -moz-math-display and -moz-window-shadow are no more available from Web content (bug 1207002, bug 1211040, and bug 1212607).
  • The font-style property now distinguishes between oblique and italic when both variants are available (bug 543715).
  • Though not supported, the properties @page/marks, orphans, page, size, and widows, were parsed and @supports was incorrectly reporting them as supported; this has been fixed and the properties are not parsed anymore, nor marked as supported (bug 1215702).
  • The internal value -moz-mac-unified-toolbar has been removed from the possible values for the appearance property (bug 1206468).
  • Several -webkit prefixed properties and values have been added for web compatibility, behind the preference layout.css.prefixes.webkit, defaulting to false (bug 837211):
    • -webkit-animation
    • -webkit-animation-delay
    • -webkit-animation-direction
    • -webkit-animation-duration
    • -webkit-animation-fill-mode
    • -webkit-animation-iteration-count
    • -webkit-animation-name
    • -webkit-animation-play-state
    • -webkit-animation-timing-function
    • -webkit-text-size-adjust
    • -webkit-transform
    • -webkit-transform-origin
    • -webkit-transform-style
    • -webkit-transition
    • -webkit-transition-delay
    • -webkit-transition-duration
    • -webkit-transition-property
    • -webkit-transition-timing-function
    • -webkit-border-radius
    • -webkit-border-top-left-radius
    • -webkit-border-top-right-radius
    • -webkit-border-bottom-left-radius
    • -webkit-border-bottom-right-radius
    • -webkit-appearance
    • -webkit-background-clip
    • -webkit-background-origin
    • -webkit-background-size
    • -webkit-border-image
    • -webkit-box-shadow
    • -webkit-box-sizing
    • -webkit-user-select
    • -webkit-linear-gradient() bug 1210575
    • -webkit-radial-gradient"() bug 1210575
    • -webkit-repeating-linear-gradient() bug 1210575
    • -webkit-repeating-radial-gradient() bug 1210575

JavaScript

New APIs

Changes

Removals

Interfaces/APIs/DOM

DOM & HTML DOM

Canvas

WebGL

  • Uniform Buffer Objects have been implemented (bug 1048747).

IndexedDB

Service Workers

WebRTC

New APIs

Miscellaneous

MathML

No change.

SVG

No change.

Audio/Video

No change.

HTTP

Networking

No change.

Security

  • RC4 is now also disabled by default on Beta and Release versions of the browser (bug 1201025) and the whitelist is now empty by default (bug 1215796).

Changes for add-on and Mozilla developers

Interfaces

No change

XUL

No change.

JavaScript code modules

XPCOM

  • The nsIDOMWindow interface is now empty. Its contents were either no longer used, had moved elsewhere, or were only used from C++. The items available from C++ code now reside in the nsPIDOMWindow interface (bug 1216401).

Other

  • Due to breaking changes in Firefox 44 (bug 1202902), add-ons packed with cfx will not work any longer. To make your add-on compatible again, please use jpm. You can find steps to migrate from cfx to jpm here.

See also

Older versions