This extension will provide core functions for keyboard operation.
Scrolling
Tab Focusing
Frame Focusing
Finding
Copy URL
Clear HTTP Auth
Combining with keyconfig extension, you can set any shortcut key to these functions simply.
If you operate Firefox by keyboard mainly, this extension will help you.
The addon file is unsigned, so to be able to install it, I first had to enter about:config in the address bar and set xpinstall.signatures.required to false.
Go to Addons -> keyconfig -> Preferences.
There are no "Previous Tab" and "Next Tab" entries by default, but you can add them by clicking Add a new key and using the following code snippets (thanks to the author). The "Global" checkbox can be left unchecked.
Next Tab: gBrowser.mTabContainer.advanceSelectedTab(1,true);
Best Answer
Keyconfig will allow this.