AssignmentZero est une expérience (work in progress, so far) de journalisme communautaire ("social", "deuxpointszéro", participatif, collaboratif, comme vous voulez) et open source.

"Inspired by the open-source movement, this is an attempt to bring journalists together with people in the public who can help cover a story. It's a collaboration among NewAssignment.Net, Wired, and those who choose to participate.
The investigation takes place in the open, not behind newsroom walls. Participation is voluntary; contributors are welcome from across the Web. The people getting, telling and vetting the story are a mix of professional journalists and members of the public -- also known as citizen journalists. This is a model I describe as "pro-am."
The "ams" are simply people getting together on their own time to contribute to a project in journalism that for their own reasons they support. The "pros" are journalists guiding and editing the story, setting standards, overseeing fact-checking, and publishing a final version. [...]
This is not just an open, but also a pro-am, project. Some things will be decided by editors, others will be left to participants. We don't know what the optimal mix is yet, but in the course of the project we'll find it. [...]"