The Free Dictionary
TheFreeDictionary.com is an online dictionary and encyclopedia which gathers information from a variety of sources. It mirrors the content of Wikipedia. It is run by Farlex, Inc.
Mirroring Wikipedia
TheFreeDictionary.com applies a number of modifications to Wikipedia content, notably replacing all instances of Wikipedia with Encyclopedia and replacing links to Wikipedia or its sister sites with links to thefreedictionary.com. Also, no articles with wiki in their title are included.
Such editing is compliant with Wikipedia's license, the GFDL. However, the original link back to the source Wikipedia article (as a form of credit and accessing the page history per the GFDL) on TheFreeDictionary.com is obscured through the use of Javascript, leading to those using archaic browsers which do not support Javascript, such as Lynx, or search engine indexing bots do not have the attribution link displayed. This has in part led to TheFreeDictionary.com being ranked higher than Wikipedia through Google's PageRank system. The text attributing the article to Wikipedia is also displayed in a smaller font than the rest of the article. Such behaviour is dubiously compliant with the GFDL, at best.