I have no idea what this is besides it is commonly used in Australia. I mean as in tastes and how it's used. I see it mostly on bread but I have heard several good and bads on it. I am anxious to try it!
Most Aussies are reared on Vegemite as children. I find that most adults who try Vegemite for the first time are usually the people who strongly dislike the flavour, however, most kids love the stuff, and grow up eating it.