Anaerobic composting - Slime composting, this is composting without air. Low maintenance, throw it in a pile and wait a couple years. If you just stack your debris in a pile it will generally compact to the point where there is no available air for beneficial organisms to live. Instead you will get a very slow working bacteria growing that does not require air. Your compost may take years to break down (this is what happens when you throw your food waste in the garbage that goes to the landfill).
Anaerobic composts create the awful smell most people associate with composting. The bacteria break down the organic materials into harmful compounds like ammonia and methane.