Wikipedias have a wide range of uses. They are available in many languages and cover all KLA's. Anyone can add or delete information within these pages, just like a Wiki. Although Wikipedia is not considered an educational reference for information, however it can still be used in the classroom.
Wikipedias can be created for use in the classroom but would need to be monitored closely by the Teacher. However, it would be more useful as a learning tool rather than just a contribution learning tool. On the Wikipedia you have many choices of what can be done with them, like, going to other related links, locating photos that are related to the information. There is a community portal, a help desk, a Wikisource, Wikibooks, Wikionary and one that is very useful for all ages, Wikiversity. Wikiversity is an open learning form where learning resources and projects can be found and used it also includes professional and informal training. A great resource for collaborative learning.