Summary
Wikipedia's Simple English Free Encyclopedia is an interesting concept that has actually created quite a following. The idea behind the wiki is to collectively create a free and open encyclopedia with articles that can be read by people with only a basic knowledge of English, and to help them learn and improve while discovering new topics.
I would recommend the Simple English Wikipedia for folks interested in learning about topics that intrigue them while simultaneously learning English. I enjoy this method because it is more meaningful to me than random texts that might not interest students, or have little information pertinent to what they are motivated to read about. Keep 'em interested!
When combined with the wonders of Wiktionary English, there is a lot of educational material and practice content to work with on Simple English Wikipedia. Enjoy!
From Website
About Us
This is Simple English Wikipedia. Wikipedias are places where many people work together to make encyclopedias in many languages. We only use very simple English words and simple ways of writing here.
There are tens of thousands of articles in this wiki. All of the pages are free to use. There is a discussion in the GNU Free Documentation License.
You are invited to help! You may change these pages and make new pages. Read the help pages and other good pages to learn how to write pages here. If you need help, you may ask questions at Simple talk.
What to Do
Use easy words and shorter sentences. This lets people with little English read them.
Write good pages, with care. The best encyclopedia pages have useful information. They are also carefully written.
Use the pages to learn and teach. These pages can help people learn English. You can also use them to make a new Wikipedia to help other people, if you change the words to your own language.
Visit Simple English Wikipedia.
Part of the content for this article is adapted from an article on Freestyle Language. If you are interested in reading about language bits and bobs that are "freestyle" in nature, have a look.