The Exxon brand is a major oil and gas company that was founded in 1870. It is the world's largest publicly traded international oil and gas company, and its primary brand is Esso, which is a four-letter word. Esso is a trademark of ExxonMobil Corporation and is used in over 80 countries worldwide. The company has operations in exploration, production, refining, marketing, and transportation of crude oil and natural gas.