Meet the new version of Firefox - Firefox 9. It was just released by Mozilla and we rushed to install it on app cloud.

Firefox 9 Version

Try Firefox 9 in Browserling now!

What's new in Firefox 9

  • Added Type Inference, significantly improving JavaScript performance.
  • Improved theme integration for Mac OS X Lion.
  • Added two finger swipe navigation for Mac OS X Lion.
  • Added support for querying Do Not Track status via JavaScript.
  • Added support for font-stretch.
  • Improved support for text-overflow.
  • Improved standards support for HTML5, MathML, and CSS.
  • Fixed several stability issues.
  • Fixed several security issues.

Fixed issues in Firefox 9

  • Use-after-free in nsHTMLSelectElement.
  • Crash scaling <video> to extreme sizes.
  • Crash when plugin removes itself on Mac OS X.
  • Key detection without JavaScript via SVG animation.
  • nsSVGValue out-of-bounds access.
  • Potentially exploitable crash in the YARR regular expression library.
  • Miscellaneous memory safety hazards.

Unresolved issues in Firefox 9

All Systems

  • Some add-ons may cause crashes on startup for some users. Please start Firefox in safe mode and disable any problematic toolbars.
  • The Web Developer menu includes a new "Inspect" option. This is an early version of a developer tool that has already evolved substantially. If you're a web developer, we recommend you download Firefox Aurora and try out the improved version of this tool.
  • Users of the Twitter search plugin may see Twitter appear in the search provider list multiple times.
  • Choosing the "Pop out" menu item while watching fullscreen YouTube videos may cause Firefox to hang.
  • Roundcube, webmail software used by many hosting companies, incorrectly displays an ellipses in place of long email titles. The Roundcube team has been notified of the issue.
  • Arabic text on does not display correctly. The BBC has been notified of the issue.
  • Firefox will now display a corrupted content error when it detects certain types of misconfigured servers. This is not a Firefox issue, please contact the website owner.
  • For some users, scrolling in the main GMail window will be slower than usual.
  • If you try to start Firefox using a locked profile, it will crash.

Microsoft Windows

  • Some users of Adobe Reader X have experienced instability when viewing PDF documents in the browser. Uninstalling and reinstalling Adobe Reader X has been determined to resolve the issue.
  • Some ALPS touchpad drivers break scrolling in Firefox. A workaround has been identified.

Mac OS X

  • For some users, the preference dialog is not shown and a rendering error is shown instead. This is caused an add-on incorrectly setting Firefox preferences.
  • Users running Mac OS X 10.7 may see a crash when the file chooser dialog is shown. Apple has been notified of the issue.
  • Users running Mac OS X 10.7 are no longer able to use gestures to navigate. This is due to underlying operating system changes and is fixed by Mac OS X 10.7.2.
  • This version of Firefox will not work on Macintosh hardware with Power PC CPUs.

Linux and Unix

  • The video control buttons may not work when viewing QuickTime videos with libtotem.
  • Users compiling from source might need a newer gcc and libstdc++ as the build requirements have changed.


Developer details for Firefox 9

  • The value attribute of <li> now can be negative as specified in HTML5. Previously negative values were converted to 0.
  • You can now specify the start and stop time of media in the URI of the media when using <audio> and <video> elements.
  • The font-stretch property is now supported.
  • The columns property is now supported, with the -moz prefix. This is a shorthand for the following properties: column-width and column-count.
  • The Node.contains() method is now implemented; this lets you determine if a given node is a descendant of another node.
  • The Node.parentElement attribute has been implemented; this returns the parent Element of a DOM node, or null if the parent isn't an element.
  • Workers implemented in blob URLs were broken in Firefox 8, and work again starting in Firefox 9.
  • The WebGL context drawingBufferWidth and drawingBufferHeight attributes are now supported.
  • The non-standard restyle value for the actiontype attribute on <maction> elements has been removed.
  • While still unsupported, using the <mlabeledtr> element no longer breaks rendering completely. See bug 689641 for progress on actual support of this element.
  • You can now send the contents of JavaScript typed arrays using XMLHttpRequest.
  • WebSocket connections now permit non-characters in otherwise valid UTF-8 data frames to be received, instead of failing.
  • The web console now supports basic string substitutions in its logging methods.
  • You can now create visually nested blocks of output in the web console, to help make it easier to read.
  • The tab element now has a pending attribute, whose value is true, when the tab is in the process of being restored by the session store service. This can be used for styling the tab in themes. The attribute isn't present on tabs that aren't pending.
  • The tab element now has an unread attribute, whose value is true, when the tab has changed since the last time it was the active tab or if it hasn't been selected since the current session began. The attribute isn't present on tabs that are not unread.
  • FileUtils.jsm now has a File constructor that returns an nsIFile object representing a file specified by its pathname.
  • The content preference service now handles private mode browsing.
  • NSPR now has an "append" module, which lets you append new data to the end of an existing log.
  • nsIGlobalHistory3 has been removed during streamlining of the Places and DocShell code.
  • The nsISound interface has a new constant, EVENT_EDITOR_MAX_LEN. The allows for playing the system sound for when more characters than the maximum allowed are typed into a text field. Currently, this is only used on Windows.
  • The --enable-application=standalone option for building standalone XPConnect has been removed; it hasn't worked since 2007 anyway.
  • Support for building Necko and Transformiix XSLT standalone has been removed; you can no longer use --enable-application=network or --enable-application=content/xslt.
  • The spell checker no longer has an arbitrary 130-character word-length limit on the length of words it will attempt to spell check. This limit was previously in place to prevent crashes that were occurring in the spell checker, but the underlying bugs have since been fixed.
  • You can now register components to add features to the window.navigator object by using the "JavaScript-navigator-property" category. See Adding APIs to the navigator object for details and examples.

Detailed developer-side changes are well-documented here.

Have fun cross-browser testing in Firefox 9 with Browserling!