Uses of kerberos?

[Klingon]

Hi

I am very new to the kerberos subject. I was wondering where it is used. Is
it used in any of our standard windows operating systems like
95,98,nt,me,2000,mx,xp? Or is it maby standard in any linux platforms
(which?)? If this isn't. Which people or organizations are glad to use it
for all safety kinds (maybe nasa?,..... I really don't know actually)?

This are a lot of questions at once, but can someone please explain me some.

Thx