This post is mostly for my reference, but hopefully it is useful to others as well. :)
Extensions:
| Extension Name | Description | License | Development | Restart Required |
|---|---|---|---|---|
| BetterPrivacy | Removes Flash "Super-Cookies" / LSOs (Local Shared Objects) | Freeware | Inactive | Yes |
| cliget | Download protected files using curl, wget, or aria2. | MPL 1.1 | Active | No |
| Cookie Controller | Buttons for managing cookies, cookie permissions, and site cookie exceptions. | MPL 2.0 | Active | Yes |
| DuckDuckGo Plus | Adds DuckDuckGo as the default address bar, search bar and right-click search engine. | Apache 2.0 | Active | No |
| Greasemonkey | A userscript manager. | MIT/X11 | Active | Yes |
| HTTPS-Everywhere | Encrypt the Web! Automatically use HTTPS security on many sites. | GPLv3 | Active | Yes |
| Policeman | Can be used as a replacement for RequestPolicy and NoScript. Policeman gives you precise control over what web requests are allowed. | GPLv3 | Active | No |
| Privacy Badger | Protects privacy by evaluating third-party sites and blocking those that appear to be tracking you. | GPLv3 | Active | No |
| Random Agent Spoofer | Rotates complete browser profiles ( from real browsers / devices ) at a user defined time interval. It includes many extra privacy enhancing options. Note: The Github version has more features which AMO won't allow. | GPLv3 | Active | No |
| Reddit Enhancement Suite | A suite of tools to enhance Reddit. | GPLv3 | Active | No |
| Self-Destructing Cookies | Protects against trackers and zombie-cookies. Gets rid of a site's cookies and LocalStorage as soon as you close its tabs. | GPLv2 | Active | No |
| Smart Referer | Send referers only when staying on the same domain. | WTFPL | Active | No |
| SSleuth | SSleuth ranks an established SSL/TLS connection and gives a brief summary of the cipher suite, certificate and other SSL/TLS parameters. | GPLv3 | Active | No |
| The Addon Bar (restored) | Restores the Addon bar. | MIT/X11 | Active | No |
| uBlock | A excellent light-weight blocker that was recently ported to Firefox. | GPLv3 | Active | No |
Userscripts:
| Name | Description | License | Development |
|---|---|---|---|
| AdsBypasser | Skips count-downs/continue pages and more. | BSD | Active |
| Bigger Twitch | Stretches the twitch player so it uses as much space as possible. | MIT/X11 | Active |
| Bypass YouTube age verification Improved | Bypasses YouTube age verification without logging in. | GPLv3 | Active |
| DuckDuckGo Extended | Adds a customizable list of quick links to other search engines. | MIT/X11 | Active |
| Google Hit Hider by Domain (Search Filter / Block Sites) | Block unwanted sites from showing up on search results at Google, DuckDuckGo, & Startpage. | BSD | Active |
| Hide unwanted streams on Twitch | Blocks channels, games, etc that you are not interested in. | MIT/X11 | Active |
| ViewTube | Watch videos on various sites without needing Flash. | GPLv3 | Active |
| Youtube Video Ratings Bar with Power Meter | Places a ratings bar beneath video thumbnails and indicates viewer 'enthusiasm' alongside likes and dislikes. | CC BY-NC-SA 3.0 | Active |
If you have interesting Firefox extensions or Userscripts (preferably open source), please feel free to post them in the comments section below.
Comments?