Firefox Extensions to Open Source

Apertium is a free, open-source machine translation platform utilizing rule-based methods. It provides versatile translation capabilities, including online translation, browser integration, and potential for localized content.

Pencil Project is a free and open-source GUI prototyping tool that helps designers and developers create wireframes and mockups easily. Available as a standalone application and a Firefox extension, it offers a wide range of built-in shapes and templates for various platforms.

RequestPolicy is a powerful, open-source browser extension for Firefox that provides granular control over cross-site requests. It helps protect users from various web vulnerabilities like Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF), and Clickjacking by allowing you to explicitly approve or deny requests to external domains.