Wikipedia is the sixth most popular website in the world. It’s the quickest way to get the lowdown on the Battle of Nashville, find out exactly how old Ruth Bader Ginsburg is, or discover who invented Hot Pockets. You can find more authoritative specialized resources online—from the Stanford Encyclopedia of Philosophy to IMDb— but nothing is as comprehensive. The English-language edition, the largest of Wikipedia’s 287 language editions, now includes more than 4.5 million entries, and 11 other editions have more than a million each.
Few of the tens of millions of readers who rely on Wikipedia give much thought to where its content comes from or why the site, which is crowdsourced and open (at least in theory) for anyone to edit, doesn’t degenerate into gibberish and graffiti. Like Google or running water, it is simply there. Yet its very existence is something of a miracle. Despite its ocean of content, this vital piece of informational infrastructure is the work of a surprisingly small community of volunteers. Only about 3,000 editors contribute more than 100 changes a month to the English-language Wikipedia, down from a high of more than 4,700 in early 2007. Without any central direction or outside recognition, these dedicated amateurs create, refine, and maintain millions of content pages.