COBOL, or Common Business Oriented Language, is one of the oldest programming languages in use, dating back to around 1959. It's had surprising staying power; according to a 2022 survey, there's over 800 billion lines of COBOL in use on production systems, up from an estimated 220 billion in 2017. For large organizations, it tends to be a complex and costly proposition, given the small number of COBOL experts in the world.