Zen Stable ReleaseIntroducing Library! A better place to organize and access your history, media, downloads, spaces and more.Securityhttps://www.mozilla.org/en-US/security/advisories/mfsa2026-97/New FeaturesIntroducing Library! A better place to organize and access your history, media, downloads, spaces and more.You can now resize the sidebar even when its hidden. If the sidebar is resized too small, it will automatically hide itself.Updated to Firefox 157.0WebRTC video calls can now use hardware AV1 decoding on devices that support it, instead of always decoding AV1 video in software.FixesSignificant performance improvements on startups/new windows when there are lots of tabs open.Certain icon animations like the boost indicator or musical notes on the sidebar are now more performant. (#15299)Fixed status panel and glance controls not using the correct theme colors. (#15280)Fixed some HDR videos encoded in 8-bit color formats looking dull and gray on Windows instead of displaying in HDR.Improved audio and video synchronization when repeatedly changing the playback speed of videos, for example on YouTube.Fixed an issue on Windows where making a video full screen would leave the Windows taskbar showing over the video.ChangesWhen a link gets routed to a specific space, it will prioritize the window that has that space open.Some elements like the sidebar and the command bar now appear with blur effects.On MacOS, buttons at the bottom of the sidebar now appear larger.Swiping to the right on the last space will now try to create a new space.When the sidebar is at the right, the buttons at the bottom are now reversed.