In the nightly builds of Firefox, on which the release of Firefox 146 will be based on December 9, testing of the 'Split View' mode has begun for viewing two tabs side by side in one window. This mode is activated via the 'browser.tabs.splitView.enabled' setting on the about:config page, after which an 'Add Split View' option will appear in the context menu when right-clicking on tabs.
When this option is selected for an individual tab, the window content is split into two sections, with the content of the new tab opening in the right section. If the option is selected for a group of two tabs, those tabs will be expanded side by side. In 'Split View' mode, the size of the right and left viewing areas can be arbitrarily adjusted by dragging the separator bar with the mouse. The active tab during simultaneous viewing is highlighted with a red border.
Source: opennet.ru
