The sixth most widely used website in the world is not run anything like the others in the top 10. It is not operated by a sophisticated corporation but by a leaderless collection of volunteers who generally work under pseudonyms and habitually bicker with each other. It rarely tries new things in the hope of luring visitors; in fact, it has changed little in a decade. And yet every month 10 billion pages are viewed on the English version of Wikipedia alone. When a major news event takes place, such as the Boston Marathon bombings, complex, widely sourced entries spring up within hours and evolve by the minute. Because there is no other free information source like it, many online services rely on Wikipedia. Look something up on Google or ask Siri a question on your iPhone, and you’ll often get back tidbits of information pulled from the encyclopedia and delivered as straight-up facts.

Yet Wikipedia and its stated ambition to ‘compile the sum of all human knowledge