When rereading the Memory, Sorrow and Thorn series, I found the following passage that tickled my fancy. ;-) It reminds me of open source, but it's really not similar enough to be an allegory of that (and most likely wasn't intended that way). Still, it's interesting to see a description of a system where sharing is encouraged.
"But your people have no king?" she asked.
"No." The small man thought for a moment. "We have elders, or we call them that, but some of them are no older than I am. Any man can become one."
"How? By asking to?"
"No. By giving feasts." He smiled shyly. "When a man has a wife and children -- and whatever other family lives with him -- and can feed them all with some left over, he begins to give what is left to others. In return, he might ask for something like a boat or new fishing floats, or if he chooses he can say: 'I will ask payment when I give my feast.' Then, when he is owed enough, he 'calls for the crabs,' as we say, which means he asks all those who owe him things to pay him back; then he invites everyone in the village for a feast. If everyone is satisfied, that man becomes an elder. He must then give such a feast once every year, or he will not be an elder in that year."
"I think," Tiamak said quietly, "that it is a good way. It makes certain that no one starves and that no one hoards his wealth. Until I studied in Perdruin, I could not imagine that there was another way of doing things."
"But if a man doesn't wish to be an elder," Miriamele pointed out, "then there's nothing to make him give up the things he is gathering."
"Ah, but then no one in the village thinks very highly of him." Tiamak grinned. "Also, since the elders decide what is best for the village, they might just decide that the excellent fish pond beside which a rich and selfish man has built his house now belongs to all the village. There is little sense in being rich and not being an elder -- it causes jealousy, you see."
(Tad Williams, To Green Angel Tower, chapter 13, book 3 of Memory, Sorrow and Thorn)