It's a shame development has halted. However, the same functionality can be found in uBlock Origin, by the same developer, and it's actively maintained. But I find uMatrix UI is better than uBO.

The very first and the most awesome addon I add everywhere I can.

Awesome. I prefer uMatrix to NoScript.

No question, this is the most important addon for who cares about data privacy.

Mein Nr. 1 Add-On aller Add-Ons!
Ich kann ganz gezielt, individuell Einzelne zulassen oder blockieren (falls es nicht eh schon vom Standard blockiert ist).
Diese Einstellungen sind pro Webseite speicherbar.
Dieses Add-On trägt den Namen Matrix völlig zurecht.
Einfach geil.

The best web firewall for browsers, a shame it's not developed anymore, but will use it until the end or until I can learn 2code.

It would be great to adapt it for computer park administration, it would avoid so much malware from the web that isn't filtered by routing/rev-proxy.

If you're an advanced user, this is the best and most important extension for the modern web.
Using the web without it is actually unbearable. Seriously.
Thank you Raymond Hill!

Very useful and well-designed add-on. I was really surprised how intuitive and powerful the graphical interface is. Must have.

the most helpful tool I've ever used, if I ever use a different browser it better have this on it. not very easy to use until you mess with it for a bit then it's repetitive but gets very easy to use and you can even block yt ads with this and block the anti ad blocker.

This is a fantastic extension. You'll learn a lot about the web when you poke around with it when you browse. ... but you can get much of the same with its "sibling" extension, uBlock Origin.