Nightly Tester Tools is a Mozilla Firefox extension that 'tricks' other extensions into working with the new version of this popular browser.
Once installed, Nightly Tester Tools adds an option in the browser's Extensions window to 'Make all compatible' and thereby use the immense majority of extensions that would otherwise be incompatible with your version of Firefox with no problems at all. Nightly Tester Tools also adds some secondary options to the browser menu, such as to take screenshots, show incidents that occur when Firefox is running, or copy a list of all installed extensions to your clipboard.
Installing Mozilla Firefox extensions can be done from the website or by dragging the .xpi file to the Extensions window in your browser.
Works with Firefox 2.0b1-3.0a1, Thunderbird 2.0b1 - 3.0a1, and SeaMonkey 1.5a.