Exxon Mobil Corporation or ExxonMobil (NYSE: XOM), is an American oil an gas corporation and a direct descendant of John D. Rockefeller's Standard Oil company. Formed on November 30, 1999, by the merger of Exxon and Mobil, ExxonMobil is the world's largest company by revenue, at $404.5 billion for the fiscal year of 2007. It is also the largest publicly held corporation by market capitalization, at $501.17 billion on April 18, 2008. Exxon's reserves were 72 billion oil-equivalent barrels at the end of 2007 and at current rates of production are expected to last over 14 years. While it is the largest of the six oil supermajors with daily production of 4.18 million BOE (barrels of oil equivalent) in 2007, ExxonMobil's daily production is still surpassed by several of the largest state-owned petroleum companies and it is only 14th in the world when ranked by held oil and gas reserves.