Wikipedia:Buying Wikipedia articles in print or another form
Wikipedia is a part of the Wikimedia Foundation, a non-profit charitable organisation whose mission it is "to empower and engage people around the world to collect and develop educational content under a free license or in the public domain, and to disseminate it effectively and globally."
To serve this end, all Wikipedia content is licensed under "free" (libre) copyright licenses. Similar licenses in the domain of computer software are described as being, "a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'." Wikipedia articles may be freely copied and sold commercially so long as publishers adhere to the terms of the copyright license under which the content is made available.
Publishers are allowed to sell copies of Wikipedia, and consumers, if they so choose, are allowed to pay for what they could get at no charge through the Wikimedia Foundation's websites.
For more information, see Wikipedia:Copyright.
PediaPress
In partnership with PediaPress, Wikipedia enables readers of its online encyclopedia to create collections of Wikipedia articles and to order these directly as high-quality print-to-order books. 10% of the gross sales cost from books sold in this way go to the Wikimedia Foundation. Books created in this way can also be downloaded in PDF or OpenDocument format free-of-charge.
The Wikimedia Foundation also plans to release a CD/DVD or print version of Wikipedia as an encyclopedia.
Other third-party publishers
Wikipedia articles can be purchased in book form from third-party publishers. Wikipedia content may also be integrated into larger commercially available books. Publishers that do so are required to adhere to the relevant copyright licenses (such as attributing article authors) but are not restricted in any way from charging for the work. They are not obliged to actively inform purchasers beforehand that the content of these books has been taken from Wikipedia, or to inform contributors that their work is being used. The content being licensed may have requirements that the license be published or distributed along with the content, and authors attributed.
Publishers that republish Wikipedia content in this way include Books LLC, ICON Group International, and four publishing houses of the German group VDM Publishing: Alphascript Publishing, Betascript Publishing, Fastbook Publishing and Doyen Verlag. These are often poorly printed and carelessly illustrated. If you have purchased a book from a third-party publisher and are unhappy with it, please contact the vendor.
The work of the Wikimedia Foundation can also be supported through direct donations. Funds raised through donations (as with funds raised through all other ways) go towards the cost of hosting Wikipedia online and for the small number of staff that the Wikimedia Foundation employ.
Wikipedia merchandise, including T-shirts, coffee mugs and satchels, is also available for sale at The Wikimedia Shop.