Exxon Mobil Corporation is a multinational oil and gas corporation headquartered in Irving, Texas. The company is the largest direct descendant of John D. Rockefeller's Standard Oil Company and was formed in 1999 by the merger of Exxon and Mobil. Exxon Mobil is involved in the exploration, production, transportation, and sale of crude oil and natural gas, as well as the manufacture and sale of petroleum products. The company operates in over 200 countries and territories around the world and has a significant presence in the United States, Canada, Europe, Asia, and the Middle East. Exxon Mobil is one of the largest publicly traded companies in the world and is listed on the New York Stock Exchange under the ticker symbol XOM.