Vegemite

This sacred black tangy paste is as Australian as the Sydney Opera House or the Harbour Bridge, Uluru or kangaroos. A thick dark spread used on toast or bread, or flavouring in soups and casseroles, it has been loved by Aussies since the early 1920s. The secret to Vegemite is to use it sparingly -- just a very fine thin layer on fresh toasted bread or crackers.

Short history
This Australian icon was developed in 1922 by Australian food technologist, Cyril P. Callister, and marketed by a Melbourne businessman, Fred Walker. Made from the yeast left-overs of the beer making process, it became one of the positive side effects of the Australian brewing industry of the 1920s.

Nutrition
Vegemite's reputation for nutrition was boosted when infant welfare centres recommended its use for toddlers to receive their quota of vitamins B1, B2 and Niacin, but the manufacturers failed to mention that it also contained 10% salt, and so in its early days it was marketed as 'health' food. It has since had its salt levels reduced, so it conforms to health considerations.

From Recipes Wiki, a Wikia wiki.