It's a value at the heart of successful open source projects. It is also at the heart of the Internet.
It's not majority rules. It's everyone agrees, or at least accepts the agreement of the vast majority.
Consensus has a bad habit of breaking down when money gets into the mix. Contracts are one replacement principle. Democracy is another. Power is a third.
But none of these alternate values deliver what consensus delivers. You realize this when consensus is lost.
- In the dispute over Internet Governance, the U.S. is fallng away from a world consensus. Democracy dictates we lose. But that result could be fatal to how the Internet works.
- In the dispute between Level 3 and Cogent, over peering, Level 3 wants its financial power to force a resolution based on contracts. It has staged an outage of Cogent traffic to get its way. It has greater power, but if you can't reach a site because it's on the wrong backbone, are you better off?
Most recent open source failures -- forked projects, changed licenses -- were at their heart a breakdown of consensus. Sometimes the problem was that one person was doing the work and everyone else was freeloading. Sometimes it was that a sponsor's money wouldn't follow the developers' consensus on future directions.
I think this reliance on consensus is also behind some of the animus we see from proprietary software licensors concerning open source. Contracts and democracy are values that Americans treasure. Consensus seems foreign, even French.
But it's not. The Declaration of Independence was not signed until a document was delivered which all delegates felt they could sign, even at the known risk of their lives and fortunes. (Most signers lost both.)
Look at it that way and maybe consensus isn't so bad.