Force enable text selection and copy. (mod by Gary)
This is modded from another well-known addon and makes it function on local files also. Nothing else changed.

Open current page in new window without toolbar.

Copy Links, Tabs & Images as Markdown via right clicks.

Disables private browsing.

Allows to switch the current tab to a different container.

Easily browse the internet using TOR proxy with just one click!

Move tabs between windows via the context menu.

Opens outlook.live.com after clicking on it. Does nothing else.

Easily clear your browser's data and speedup browsing via toolbar popup.

When a current tab is closed, the left tab (or the right tab on RTL environments) will be activated.

Make any webpage into a content editable document and modify it via toolbar popup!

Adds keyboard shortcuts for closing all not active tabs, all to the left of the active one, all to the right

An open source browser addon/extension to bookmark at once all open tabs to a folder in the Bookmarks Toolbar.

Add your own custom CSS styles to any webpage

Slideshow at tabs.

Load any URL you want when a new tab is opened. CNT is the only add-on to place the focus intelligently on the chosen web page (like a search engine's search box) or in the URL bar!

Tab unload options for Tree Style Tab.

Highlights given keywords on any web page you visit.

Set maximum number of opened tabs in a window.

Analyse chess.com game at lichess.org for free.

Easily switch between multiple proxies via toolbar popup

Open a list of the recently closed tabs.

Open a blank dark or white tab rather than the default browser's new tab page.

Open Link in New Tab help you change default how a link opened - in current tab or in new tab. Compatible with new Firefox Quantum 57

Control your tab volume.

This add-on requires Tree Style Tab. It extends Tree Style Tab to allow tab changing by mouse wheel scrolling and reloading a tab when double clicking it.

Easily clear browser's cache via toolbar popup.

Speed up your browser with 7 tweaks via toolbar popup.

Duplicates the current tab from keyboard shortcuts or when you click the icon

Source, issues: https://github.com/Skeletonxf/duplicate-tab/

Button to refresh the current page without using the cache.