Zen Browser, it's still beta software imo but tab grouping and vertical tabs have become must-have features for me (another thing Mozilla should be working on).
I use a Firefox fork too, but do you think it would continue to be around without Mozilla?
It's sad to see them squander an opportunity to do good work. Mozilla should have gone all-in on ethics/privacy in contrast to tech giants and made an offering like Proton. Or gone with the Wikipedia donate model like another commenter said. Any compromise on their values is insane mismanagement, that was their whole brand.
I use one of their competitors (Sleepme Ooler) but they're not great either. Did not know about aquarium chillers, that seems like a better option. Could probably pair it with Home Assistant too if you wanted to more easily set the temperature.
I thought it might be similar to Orion based on the submission title, but it looks like a rebranded Firefox (which is great). This is what Mozilla should be doing.