Wikipedia's Simple English Free Encyclopedia is an interesting concept that has actually created quite a following. Now with more than 10,000 articles, the Simple English version of Wikipedia offers more content than many foreign languages when compared with the likes of Wikipedia Afrikaans and Wikipedia Swahili, both of which are still in the 1,000+ articles range.

I would recommend the Simple English Wikipedia for folks interested in learning about topics they are interested in while practicing their English. Combined with the wonders of Wiktionary English, there is a lot of educational material and practice content to work with.

Check out Free Language for more tools and resources for learning English.