The best userscript manager for Firefox.

I used Greasemonkey forever, then switched to Tampermonkey after Firefox broke legacy support with its multi-process architecture. I still run both, but Violentmonkey outperforms its competitors in every way that matters.

No bloat, privacy-focused, actually optimised for Firefox and open-source. Tampermonkey being closed-source, and originally Chrome-centric (pre-Manifest V3). If you're using Firefox, use Violentmonkey.

Best open source userscript manager I've tried, it works well for my needs.

Violentmonkey is a great extension for anyone who wants to run userscripts in their browser. It’s open source, easy to use, and lets you customize websites with extra features or tweaks. Installing and managing scripts is simple, and it works smoothly without slowing down browsing. Perfect for users who like to personalize and enhance their web experience.

chrome cannot use it, so i use firefox instead