Mozilla has unveiled Firefox 45 FINAL, its desktop browser for Mac, Linux and Windows. The new release focuses its changes on the browser’s use of tabs, and also becomes the base for the new Extended Support Release.

New features include instant tab sharing in Hello and a new Synced Tabs button, but one feature has been removed: Tab Groups.

Once again, Mozilla focusses on extending its new Hello chat feature, this time by adding support for sharing the currently selected browser tab. The feature is enabled by default, but users can switch it off by clicking the ‘Stop’ button at the top of the browser window.

Users can now share browser tabs using Firefox’s Hello chat feature.

Firefox’s button-based menu bar also gains a new Synced Tabs button, making it possible for users to quickly view synced tabs from other devices – they’ll be prompted to switch the feature on if it’s not already enabled. These tabs also now appear in the dropdown area of the Awesome bar during searches.

Mozilla has removed the ability to group tabs together to “make it easier for us to improve Firefox”. Wary of a likely backlash, the company has made it clear that the feature can be preserved through the installation of an add-on and recommends users of the feature install the Tab Groups add-on prior to upgrading to version 45 to preserve existing tab groups.

Other new features in the desktop release include a new preference that – by default – blocks access to sites using the .onion suffix (part of the hidden Tor network) at DNS level. To allow this feature,

open about:config, then search for network.dns.blockDotOnion and set the value to ‘false’.

Developers gain more new and improved features, HTML5 support now includes include Push API and the Web Speech synthesis API, but one regression – support for the on-screen keyboard in Windows 8 and 8.1 – remains unresolved.

Firefox 45 also becomes the new Extended Support Release for those users who prefer less frequent updates.

Also due for release is Firefox 45 for Android, which adds a click-to-view images option, toggle for disabling the sharing of camera and microphone for family friendly browsing and an optimised Settings under the main menu.

Firefox 45 FINAL and Firefox ESR 45.0 are both available now as free, open-source downloads for Windows, Mac and Linux. Firefox 45 for Android should be released imminently.