Firefox Release Notes

Add the search field to the new tab page

Support of Prefer:Safe http header for parental control (learn more)

mozilla::pkix as default certificate verifier (learn more)

Partial implementation of the OpenType MATH table (section 6.3.6) see documentation about mathematical fonts and the MathML Torture Test for details

Block malware from downloaded files (learn more)

audio/video .ogg and .pdf files handled by Firefox if no application specified (Windows only)

Upper Sorbian [hsb] locale added

Various security fixes

Search for partially selected link text from context menu (985824)

Removal of the CAPS infrastructure for specifying site-specific permissions (via capability.policy.* preferences). Most notably, attempts to use this functionality to grant access to the clipboard will no longer work. The sole exception is the checkloaduri permission, which may still be used as before to allow sites to load file:// URIs.

Developer Tools: Add-on Debugger (learn more)

Developer Tools: Canvas Debugger (learn more)

navigator.sendBeacon enabled by default (learn more)

New Array built-in: Array.prototype.fill() (learn more)

New Object built-in: Object.setPrototypeOf() (learn more)

CSP 1.1 nonce-source and hash-source enabled by default

Developer Tools: Eyedropper tool added to the color picker (learn more)

Developer Tools: Editable Box Model (learn more)

Developer Tools: Code Editor improvements (learn more)

Developer Tools: Console stack traces (learn more)

Developer Tools: Copy as cURL (learn more)

Developer Tools: Styled console logs (learn more)

Dialogs spawned from the onbeforeunload event no longer block access to the rest of the browser

WebVTT implemented and enabled (learn more)

CSS3 variables implemented (learn more)

Mac OS X: cmd-L no longer opens a new window when no window is available (1008793)

Slow shut downs lead to 'Firefox is already running' warning (see 966469 and 985655)

GNU/Linux and Windows XP: Google Maps Street View displays a black screen (1034593)

Mac OS X and Windows: Citrix Receiver no longer works. As a workaround, mark the plugin as Always Enable in the addon manager (1025627)

PDF.js: With some fonts, some characters might not be displayed. Affects a very small number of PDF (1028735)