Here's how it works: someone builds a cabin (read: 4 walls and a roof, a bit of insulation, a coal stove, some bunk beds). They use it when they want, but leave it open the rest of the time for passing travelers. The only expectations: clean it when you're done and be sure to write in the guest book. The student group here at my university owns two particularly nice cabins that are perfect for weekend get-aways. It is truly splendid to be able to plan a trip into the middle of the bone-chilling arctic wilderness, knowing that a soon-warm cabin and almost-comfortable bed awaits.
The idea of sharing cabins fits right in with the 'svalbard faith' concerning everything else. Doors on houses are always left unlocked. Keys are left in cars and snowmobiles. Skis are left outside. Broken snowmobiles are miraculously found on top of the hill that they were stuck at the bottom of. Expensive outdoor equipment is loaned without the blink of an eye. We even have a free store. Think goodwill, but everything is free. The huge fluffy (almost brand-new) down coat that I live in up here was found there, as were most of my wool socks. The generosity, caring, and faith in one another that is found here is unparalleled by anything I've seen elsewhere in the world. I'm going to miss it dearly.