Trioxane tabs. Makes a great backup when you don't want to build a wood fire while backpacking.
Lightweight, inexpensive, foil wrapped. You can break them into pieces instead of using the entire tab. Put the unused piece back in the foil and use later.
With Triox, you don't need to carry a stove. I only carry a tin cup to heat water for coffee, tea, coco, and dehydrated meals.
For a stove, put three rocks together to support your pot, drop a piece of triox in the middle, light it and put the tin cup over the fire.
No big fuel container left over when depleted, unlike propane and liquid fuel. The remaining foil goes in a pocket to pack out.
I've heated my tent with Triox as well. Two empty tin cans make a dandy heater. A clean, empty tuna can, cup side up, for the base so you don't burn a hole in the tent floor, and a soup can with holes punched in the sides, cup side down, to cover the piece of burning Triox.