Firefox vertical tabs and more with Sidebery
On the rare occasion when I use Firefox I mostly used it with Tree Style Tabs, which allowed me to put tabs in a vertical position. Since this is the 21st century and only two, yes 2, browser has default options to do this (Vivaldi and Microsoft Edge), I was very happy to see that there is a new option for Firefox based browsers: Sidebery.
While sadly it doesn't solve Firefox aweful memory usage (just today I left my machine alone for 20-30 minutes, and it eat allow of the RAM, and no other software was open).
However Sidebery is a really featureful extension that allows people not just simple do vertical tabs, but group them into different panels, and also showing bookmarks in the same sidebar.
I am using this extension for about a day, and apart some update issues (it shows some warning if it couldn't update some tab position, and you can solve it with a push of a button), it really performs well.