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Existing Movements
Free Art
There is no Free Art Definition, but the Free Art License is in the spirit of this definition.
Free Software
Cf. the Free Software Definition.
Internet Engineering Task Force
The Internet Engineering Task Force (IETF), which is the body governing the drafting and evolution of Internet protocols - without which the Internet, an unified interconnection of physically disparate networks, couldn't even exist -, has rules concerning the rights that are granted on its published documents. Although a subtle restriction on derivative works makes some of these documents not completely free, it is a good example of how Free Content's essential freedoms can be fruitfully applied to promote scientific and technical progress.
Open Knowledge
Cf. the Open Knowledge Definition.
Open Source
Cf. the Open Source Definition, but note the philosophical differences to the Free Software movement; also note that the term is, in spite of its definition, somewhat diluted, especially in contexts other than software.
Free/Libre Knowledge
Libre Knowledge is championed by Libre.org and others such as the Free Knowledge Institute.