Windows
You can install Firefox and ABP and if you do not like it go back to using Internet Explorer. Internet Explorer is not removed or modified in any way, the two browsers can live together happily.
Absolutely not. ABP is one of the most Gecko-friendly extensions there are (thanks Wladimir!) andLanik wrote:FireFox only, sorry.
works in SeaMonkey, Songbird, Flock, Thunderbird as well... there even is a K-Meleon version.
Internet Explorer is not a Gecko application though, so it won't work there.
You're right chewey however I don't think if I said Gecko only the OP would know what I meant. 
"If it ain't broke don't fix it."
Very probably notLanik wrote:I don't think if I said Gecko only the OP would know what I meant.
But as a SeaMonkey user myself, I tend to jump on occasions like that as a defender of the weak.
I'm regularly annoyed by clueless website authors sniffing for Firefox versions instead of Gecko, and sending
my "unsupported browser" away despite the fact that it contains the exact same engine as that Firefox
version they recommend me to use. Even google are guilty of that on some occasions, and they really should
know better. Because Gecko is Gecko.
You can consider me a "Gecko evangelist"