The Secular Web is operated by Internet Infidels Inc. and is dedicated to “defending and promoting a naturalistic worldview on the Internet.” It is based in Colorado Springs, Colo. Contact through the website.

The Secular Student Alliance is based in Minneapolis and describes itself as “an umbrella organization uniting atheist, agnostic, humanist, rationalist, skeptic, and freethought students and groups on high school and campuses across the world.” The SSA has a list of affiliates around the country and the world.

The Military Association of Atheists and Freethinkers is a support organization for nontheists in the armed forces.

The Institute for Humanist Studies is based in Washington D.C., and aims to promote “humanism, a nonreligious philosophy based on reason and compassion. IHS advances human rights, secular ethics and the separation of religion and government through advocacy, innovation and collaboration.” Contact administrator Maggie Ardiente.

The Freedom From Religion Foundation is based in Madison, Wisconsin, and has become one of the leading activist groups on the nontheist scene.

Atheist Alliance International (AAI) is a global federation of atheist and freethought groups and individuals, committed to educating its members and the public about atheism, secularism and related issues. It is based in California and has a list of affiliates.

The American Humanist Association is based in Washington D.C. and includes state chapters. The AHA definition of humanism encompasses a variety of nontheistic views including atheism, agnosticism, rationalism, naturalism and secularism.

The Secular Coalition for America was founded in 2005 as the “only organization in the nation whose primary purpose is lobbying Congress on behalf of atheists, humanists, freethinkers, and other nontheistic Americans.” The SCA is endorsed and supported by numerous secularist groups.

The Institution for the Secularization of Islamic Society is a web-based group that aims to promote an “Islamic Enlightenment”.