TabCenter 
Tabbed browsing is a concept that has existed for a long time without being seriously re-evaluated. In that time, browsing behaviors have changed. The web is now the central interaction point on desktop and laptop computers. For many users, their browser is the only application they ever open.
Tab Center is an attempt to solve some of the issues that have emerged from the way people use tabs (most notably the “too many tabs” problem) and provide a more versatile UI basis for future innovation. The first version of this Firefox add-on arranges tabs in a vertical rather than horizontal fashion. It is heavily inspired by and borrows ideas from the excellent VerticalTabs add-on.
Feel free to install the add-on, read the full proposal, or file a new bug! We also have a Contributor’s document, if you want to get involved and maybe fix some bugs.
Incompatibility Notes
We are incompatible with a number of add-ons:
- Hide Caption Titlebar Plus
- HTitle
- Tab Mix Plus
- Tab Groups
- Tab Groups Helper
- Tree-Style Tabs
- TooManyTabs
- All-In-One Sidebar
- Firebug
Please let us know if you find any problems with extensions not mentioned.
Development
After cloning this repository, run npm install and npm install jpm then:
npm run locales && jpm runto spawn a new Firefox profile with the addon installednpm run locales && jpm xpito generate an installable XPI file locally
Read more about jpm on MDN
Tweak
Some preference can be switched using about:config :
extensions.verticaltabs.largetabs0Never display tabs with thumbnails1Display thumbnails if there is not too many tabs open2Always display thumbnails