3. Apache Software Foundation

The Apache Software Foundation exists to provide organizational, legal, and financial support for the Apache open-source software projects. Formerly known as the Apache Group, the Foundation has been incorporated as a membership-based, not-for-profit corporation in order to ensure that the Apache projects continue to exist beyond the participation of individual volunteers, to enable contributions of intellectual property and funds on a sound basis, and to provide a vehicle for limiting legal exposure while participating in open-source software projects.

Or, as Roy T. Fielding, the chairman of the ASF describes it: The mission of the Apache Software Foundation is to facilitate and support collaborative software development projects that use the Apache methods of collaboration over the Internet to create, maintain, and extend the infrastructure of the Web and enforce the standards that define it.

You can learn more about the foundation here.