Do you consider the developer edition an extension, or is your point about extensions relating to GP's reference of Owl? Firefox Developer Edition is a first p

Do you consider the developer edition an extension, or is your point about extensions relating to GP's reference of Owl? Firefox Developer Edition is a first party version of the software from Mozilla. It runs slightly ahead of the standard Firefox version I think. FWIW, Waterfox also uses dark browser chrome by default, although if you're worried about security risks in installing extensions, a third-party fork of Firefox may not sit well with you either. Regardless, I've used both pieces of software and had very positive experiences.