Esbit works well for elementary cooking - boiling water and the like. It does have the advantage of being relatively safe to carry around and store long term. Esbit does well as a fire starter. Disadvantage is that it will deposit soot on your cooking container, but it washes off relatively easily. I use mine with a small titanium holder and an aluminum foil windscreen, a critical item in most outdoor weather. You can also buy an Esbit "stove" but it is needlessly heavy and bulky.

It is available for REI and other on line retailers, about 50 cents per tablet. Most local outdoor retailers in my neck of the woods carry it as well. Surface shipping only.