Wikipedia is the open source software model applied to a writing a collaborative encyclopedia. It works well.
The Oxford English Dictionary had a similar start. From 1857 to 1928, thousands of people sent examples of word usage not in their dictionaries. A few editors complied this into a dictionary. Sounds pretty similar to wikipedia to me, but with more primitive tools.
Was this the first example of this model? Do you know of other examples? Why is it that we don't see this in more artistic fields, i.e. composing music?