Want to learn Kantian morality? Please don't go to Wikipedia for philosophy - or anything else. Besides, the Stanford Encyclopedia of Philosophy has been around longer. Now 20 years old, America's best resource for philosophy was, like Science 2.0, designed to be much more modest than it became.

It was designed by Edward Zalta, a senior research scholar at Stanford's Center for the Study of Language and Information and the executive editor of the site, to be something of a glossary. Now it has 1,478 entries, 2,000 contributors and about four million pageviews a month, according to the team.

It shows that crowdsourcing can work, as long as people know what they are talking about and can't be hijacked by special interests. 

Here's to 20 more years, SEP!