eMarix

[Ygarr]

Please add eMatrix to https://justoff.github.io/, it is for palemoon. But can be easily converted for Seamonkey.
https://gitlab.com/vannilla/ematrix
by http://addonconverter.fotokraina.com
The add-on is positioned(and looks like) as necessary and must have for visiting Internet at all.
P.S. It can broke the Web, but it worth to be installed.

[Ygarr]

also it is
https://github.com/kristerkari/umatrix-recipes

[garoto]

You're missing the point of what this repo/extension is supposed to be.

[Chirunos]

Is already available for Basilisk Browser and Pale Moon