Sidebery is a Firefox extension that allows users to manage tabs and bookmarks in a sidebar. It offers a highly configurable sidebar with panels of different types, such as vertical tabs panels with a tree or flat layout, bookmarks panels, and a history panel. Users can also perform searches within these panels and customize the context menu and styles. Other features include the ability to take snapshots and a build process for developers. The extension can be installed by following the provided links and instructions. Donations are also accepted to support the project.
https://github.com/mbnuqw/sidebery