Re: Firefox and Extensions' section
It appears that the "most official" version of Firefox Portable, which tends to follow on the heels of the latest release very quickly, can be found here:
There are a couple of sources where Firefox gets repackaged in portable form, but I didn't notice one on the Mozilla.org site.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
A great deal of intelligence can be invested in ignorance when the need for illusion is deep.
~ Saul Bellow, To Jerusalem and Back