About Firefox additions

Additions it is the small modules changing either supplementing appearance or functionality Firefox. There are two kinds of additions: extensions and themes.

Extensions add new functionality in Firefox. They can add anything you like from the button on the control panel up to absolutely new functionality. They allow to adjust (set up) the application according to personal inquiries of each user, allowing to reduce to a minimum the size of the application.

Themes change Firefox appearance. They allow you to change a kind and interface of Firefox, adjusting them according to your needs. The theme can simply change appearance of buttons or it can change Firefox appearance completely.


Happens, that extension is not compatible to the current version of a browser. You can correct it in the different ways:
1. To install extension Nightly Tester Tools and in its options to allow to install incompatible extensions and to make extension compatible to the current version of Firefox.
2. To type in an address line about:config , in Filter to type extensions.checkCompatibility and change value of parameter on false. Or to add in a file user.js of profile a line

// Switching-off of check of compatibility of expansions
user_pref ("extensions.checkCompatibility", false);

Unfortunatelly some incompatible extensions can work incorrectly.