NoScript

If you use Mozilla Firefox, NoScript is a great way to improve its speed and stability on your Mac. This completely free plugin was developed to help you manage the scripts that run when you open a webpage.

With NoScript, you get to decide whether you want to run JavaScript, Macromedia Flash.... You can also block other plugins to keep them from running.

Thanks to NoScript, you can enjoy browsing the Internet not just because you'll be seeing only what you want, but also because you'll know you're browsing securely.

It even lets you choose which sites can show their full contents and which should be filtered according to your preferences.