"Vegemite" is a spread, sort of like peanut butter, that is made from yeast, and LOTS of salt. Really, really a huge amount of salt. It's practically inedible. Truly foul. But for some reason, the Aussies seem to like it.
If you want to know what it tastes like, mix about 1/8 teaspoon of brewer's yeast, 1 tablespoon of salt, and enough water to make a paste, and put it in your mouth. It's puckering.
Down Under, they spread the stuff on toast, like we do with butter.
And with my high blood pressure I am not supposed to eat much salt. And I am also advised to avoid Bill, Hillary, Gore, Kerry, et al on television! Raises my blood pressure. LOL
My personal theory is that it comes from Austrailia originally being a prison colony, and vegemite was a part of the punishment. The prisoners were fed it every day, and it became a staple for them. That and the old saying, "what doesn't kill me makes me stronger."
That's my theory, and I'm sticking to it.
So it's like anchovies.