Are there examples of books written Wikipedia-style, meaning written by multiple public collaborators working together, debating about what happens next to the characters, and then voting on plot changes?
Were any of them good?
Perhaps not exactly what you were thinking of, but it was written in 1969, long before the Internet or the concept of open source: [Naked Came the Stranger](http:// Naked Came the Stranger - Wikipedia)
The Wikipedia entry doesn’t describe the collaborative process, but ISTR that each chapter was written sequentially by a separate writer who only saw what had been written before (and maybe not all of that). So not the cooperative effort that you’re proposing.
It was intended to be bad, but it was popular!
After a little more Googling, I found this at the Museum of Hoaxes:
I leave it as an exercise for the reader to uncover other members of the slew.
(Interestingly, in my first Google search for Naked Came the Stranger, to my surprise, autofill first suggested “Naked Came the Manatee.”)
F. Paul Wilson has done this at least once. He helped write a book called Draculas (A Novel of Terror), with four other people. I thought it was pretty good.
There’s also a group of books and novellas called Wayward Pines that Wilson has written one for. Blake Crouch wrote the first book or two and a few others have written more.
I’m not sure how much collaborating was really done, but I think in the Draculas novel they handed it back and forth. I could tell a bit which parts Wilson had written.
The Floating Admiral, a 1931 mystery novel written by 14 members of the Detection Club (including Dorothy L. Sayers), is pretty much exactly what you said. 14 different authors, each of whom wrote a chapter, adding in whatever plot developments they felt like and passing them on the the next author.
Naked Came the Manatee was an attempt to write a mystery-humor book done in the same style as Naked Came the Stranger. Among others, Dave Barry, carl Hiassen, and Elmore Leonard contributed chapters.
I’ve read it. It’s awful. Each author was trying to pull the story in his/her direction, so it ended up sorta flopping around, with wildly discordant voices and tenor. Some authors would effectively “cancel out” what previous authors had written.
This has generally been my experience with these sorts of multiple-author books. There have been others. Jack Chalker, George Alec Effinger, and Mike Resnick tried a science-fiction version with only three authors, but writing round robin. It’s pretty awful too, and for much the same reason. I’ve read others, too, but can’t recall the titles.
even Shared Universe story cycles tend to be pretty messed up if people don’t try to keep things consistent. Read Medea: Harlan’s World sometime. Harlan Ellison tried to set up an alien world that authors would write stories set on. well, Hal Clement wrote a Hal Clement story set on one world, and Larry Niven wrote a Larry Niven story that seemed to be set on a completely different world, with hardly any connection between the two. There are lots of Truly Big Names in Sf contributing to this volume (with even more chiming in on the discussion sections), but it doesn’t really add up to a consistent whole:
It’s almost like Tyler Perry’s Madea was in charge.
Or we could talk about what the OP is asking about.
Just Google open source literature.
Or go to the site opensourcenovel.org/.
There are many more true open source novels than collective novels. Finding somebody who has actually read one and can comment on it is the true challenge.
Atlanta Nights. And, no, it isn’t very good. 
Apparently Google knows a little something special about you. And now we do too. 
I don’t know about voting, but another kind of collaborative work is “shared world”, such as Thieves’ World or Man-Kzin Wars: an editor manages contributions; individual writers submit short stories with their own POV character and involving other writers’ POV characters as secondary or participant (or even antagonist) characters.
Maybe it’s not what you’re thinking of, since you cite a wikipedia-style editing regime.
Oops! 