Firefox 89 will be a major new Firefox version; while all stable releases that bump the version by 1 may be considered major, there are only a few that make fundamental changes to the browser, and Firefox 89 will be such a release.
The upcoming version of Firefox is not a new ESR release version, but it will introduce the new Proton design in Firefox. We covered Photon quite a bit here already on Ghacks. Summed up, it is a visual refresh of the Firefox interface that modifies the browser’s address bar, tab bar, menus, main menu, modals, and other key areas.
Mozilla enabled part of Proton in recent Firefox Nightly versions already, but the full design is still in active development, and some switches have not been flipped yet. Even with all Proton switches enabled, it is still not complete at this stage.
Firefox 89’s original release date was four weeks after the release of Firefox 88, the next stable version release of Firefox, which is scheduled for a release on April 20, 2021. Mozilla decided to extend the Firefox 89 beta period by two weeks, and that postpones the release of the new Firefox version.
The new release date is June 1, 2021; it is still possible that the release may be delayed further, depending on how development progresses. All future version releases of Firefox go back to the regular 4-week release cycle. We have updated our Firefox Release calendar here on this site to reflect the change.
The new design will make several visual changes to Firefox that were discussed heatedly. Some liked the modern look of the menus and toolbars, others criticized Mozilla’s design for using too much space, lacking visual tab separators, or hiding the compact mode density in new installations.
Proton is still a work in progress, but it is clear already that the visual refresh will be a controversial one when it launches. (via Sören Hentzschel)