The Trangia is a great little cooking set that uses a really simple alcohol burner.
At its heart is a brass burner (in the traditional model) that holds alcohol such as mentholated spirit.
The heat from the flames on the stove boil and pressurise the alcohol inside the burner, causing it to come out of little jets as gas that then burns. It is really simple and has nothing much that can go wrong. It also generates a really quick heat with very little fuss.