Exciting news from Mozilla! Firefox Nightly Labs 131 now features a new sidebar experience and vertical tabs. These updates aim to enhance browsing and productivity by streamlining context-switching and multitasking workflows. The community is invited to test these in-progress features and provide feedback to help shape their development.

Source: https://blog.nightly.mozilla.org/2024/08/07/firefox-sidebar-and-vertical-tabs-try-them-out-in-nightly-firefox-labs-131/