Firefox 46 is GTK+3 based under Linux

A few days ago, Mozilla released a new version of Firefox for Windows and Linux. Version 46 comes with security fixes and a couple of new features under the hood. But the most notable change is for Linux users: they got the first official version built using the GTK+ 3 framework.

Firefox 46 does not bring any new major feature to the browser's end user functionality. However, version 46 comes with a number of improvements under the hood.
Here is the list of key improvements:

1. Improved JavaScript JIT compiler by using a new algorithm W^X. It makes the browser more secure.
2. WebRTC got many improvements and fixes, such as multi-cpu WebRTC mode and  Simulcast support.
3. For non-encrypted H.264 and AAC content, the Content Decryption Module (CDM) can be used as a fallback module in case the required codec is missing on the user's system.
4. The add-on signature enforcement can still be disabled in Firefox 46. See the following article: Disable add-on signing requirement in Mozilla Firefox.
   Earlier, Mozilla wanted to make it mandatory with the release of version 46, but later postponed it till Firefox 47.

Download links for Firefox 46 are below:

• Firefox stable
• Firefox Beta
• Firefox Developer
• Firefox Nightly
• Firefox ESR

Under Linux, Firefox GTK3 builds will require proper support of themes you are using. This can be a negative surprise for users who are used to their GTK2 themes. Those themes which haven't been updated for GTK3 will show broken layout of web pages. For example, checkboxes will not be rendered properly, and open/save dialogs will be shown without buttons.

If you face these issues, consider switching to an alternative GTK theme with proper GTK+ 3 support. For example, the stock "Adwaita" theme does not have these issues.