Until now, users that wanted to put an experimental Firefox add-on to the test had to log in to their Mozilla account in order to do so, which was fine if you already had such an account set up, but it was a real bother for the people that did not have an account and did not want to set one up either. Since preventing users from putting add-ons to the test is a real pity for Firefox, the browser that boasts about its customization options even more than safety, the login requirement has been dropped in favor of a much more user-friendly system.

If you want to test an experimental Firefox add-on, all you have to do is check the 「Let me install this experimental add-on」 box; once you do so the 「Add to Firefox」 button will become bright green (as opposed to being faded out) and by clicking it you will add that add-on to your Firefox browser.