They based their Wikipedia on Scalaris, an open-source distributed database system that incorporates SELFMAN’s self-configuring, self-tuning and self-healing capabilities. "Every piece of information in our Wikipedia exists four times – that’s a number that we found works well – and is spread over all the nodes ... A clever algorithm called Paxos does the heavy lifting to make sure the nodes all agree." They expected that their Wikipedia would have several advantages, including higher reliability, lower operating costs, and scalability – the ability to add new capacity easily in response to increasing demand. Full Article at Science Daily