Free Software Foundation

The Free Software Foundation or FSF is at http://fsf.org

It is also sometimes called GNU after its original project, "GNU's Not Unix." It uses a gnu-head as its symbol. It is identified with Richard Stallman, who is approximately as stubborn as any hoofed animal imaginable.

The FSF wrote the GPL and GFDL and takes some responsibility for their enforcement, although it is often criticized for having no viable way to do this in a self-funding manner.

The open source and some consortia (like W3 and Java) were both responses to issues with GPL, and other aspects of FSF's ideology and solutions. Creative Commons was likewise inspired by, but critical of, GFDL. See problems with free software and open source models for other views on this.