Figment.com is a new, free community and platform for young people to share their fiction writing, "connect with other readers and discover new stories and authors. Users are invited to write novels, short stories and poems, collaborate with other writers and give and receive feedback on the work posted on the site." (Via)
posted by zarq on Dec 5, 2010 - 19 comments

A Million Penguins, the wiki novel mentioned previously on MeFi, is complete, and a research paper about it has been released. [more inside]
posted by whir on May 5, 2008 - 15 comments

"A Million Penguins is an experiment in creative writing and community. Anyone can join in. Anyone can write. Anyone can edit. Let’s see if the crowds are not only wise, but creative. Or will too many cooks spoil the broth?"
posted by goo on Feb 1, 2007 - 39 comments

I like to write in a plain-text editor, and I've finally found a way to track edits! I've just started col[][l]aborating on a k[k]new book. This si[i][y]stem will come in handy. [][][thanks, Internet!]
posted by grumblebee on Jul 5, 2006 - 71 comments

Songfight is a site where users compose songs based weekly titles. Then the public votes and a winner is decided. While necessarily indie, there is a wide variety of styles present and many great songs (mp3 links) have come out of this site. (Check the archives).
posted by ODiV on Mar 28, 2003 - 7 comments