Vegemite is a thick, dark brown food spread. It's made from leftover brewer's yeast extract with various vegetable and spices added. Vegemite is very salty, with a strong umami, malty flavor. It is a rich source of B vitamins.
Vegemite is the Australian cousin of Marmite, concocted by a chemist during a time where imports of Marmite into Australia were disrupted by the war (see story).