The National Geographic Society (NGS), headquartered in Washington, D.C., United States, is one of the largest nonprofit scientific and educational institutions in the world. Its interests include geography, archaeology and natural science, the promotion of environmental and historical conservation, and the study of world culture and history. The National Geographic Society’s logo is a yellow portrait frame – rectangular in shape – which appears on the margins surrounding the front covers of its magazines and as its television channel logo. It also operates a website that features extra content and worldwide events. A significant change was announced by National Geographic Society and 21st Century Fox on September 9, 2015. The two organizations revealed an "expanded joint venture" that would re-organize the Societys media properties and publications into a new company known as National Geographic Partners. The agreement, to be finalized in mid-November 2015, will make National Geographic magazines and the Societys cable networks a for-profit venture to be 73% owned by 21st Century Fox, a conventional for-profit corporation. National Geographic Society will continue as a non-profit, however, with an enhanced endowment. The National Geographic Society was founded in 1888 "to increase and diffuse geographic knowledge." The Society believes in the power of science, exploration and storytelling to change the world, and its purpose is to inspire, illuminate and teach. National Geographic is governed by a board of trustees, whose 21 members include distinguished educators, business executives, former government officials and conservationists.