Controle de Scripts is an add-on for Firefox that allows you to control what JavaScript on a web site can (or can not) do to your browser.  Here is a little more about the extension from the developer:

Besides the well-known basic permissions, like hiding toolbars or raise or lower windows, with Controle de Scripts you [...]

The extEMM extension for Firefox is a power button for your browser. No, it will not give you super strength or flying abilities, I’m not talking about those powers. I mean - well, this is how the developer put it.
This extension adds a menu button to Firefox allowing the user to restart or [...]

Should there be better quality control for Firefox extensions?
I’m always flipping through the Mozilla forum looking for interesting things to read when I came across one that was called “addons.mozilla.org recent and open issues.” It sounded interesting because I didn’t realize that there were any open issues with Mozilla’s Add-on site.
There are a [...]