Wikipedia is 10 years old this Saturday. It is the fifth most visited site on the internet. Some 400 million people use it every month. I bet most readers of this column are among them. You want to check something, you Google it; as often as not, you Choose the Wikipedia link as the best way in.
What is extraordinary about this free encyclopedia, which mow contains more than 17m articles in more than 270 languages, Is that it is almost entirely written, edited, and self-regulated entirely by volunteers.