Sam Ruby has a great slide that categorizes project contributors. It matches pretty well with my experience, though I need to figure out if there are more clumps of participants out there.

Sam Ruby on Contributors

With a mix of people, what you inevitably get are:

• People who are ready, willing, and able to move the ball in a direction they consider forward.
• People who are only good at telling you what they don't want.
• People who drop in a requirements and then expect somebody else to run with it.
• People who wait to be asked to contribute

Sam's been a central player in the whole echo/atom/rss replacement discussion. It's amazing that this collective work has moved forward without the structure of some sort of chartered organziation to support it.

Ross : Link : Discussion Board