The simple english Wikipedia makes it easy for everyone to learn!
So the image above kinda looks like a joke but I guarantee you it's completely legitimate. The Simple English Wikipedia offers 'dumbed down' versions of standard Wikipedia articles.
It's great if you're just looking for a short summary of a potentially confusing topic like quantum mechanics (or any math article really), check out the simple version for a very easy to understand introduction/outline. When you feel like you've got a good grasp on the basics, then you can delve into the real Wikipedia article.
You can visit any wikipedia page in simple form by changing the url from http://en.wikipedia.org/wiki/Database to http://simple.wikipedia.org/wiki/Database.
If you know any other cool things like this post them in the comments!