An Acronym for Common Business Oriented Language.
A rather weird old language for manipulating sequential databases. The "common" in its name is unfortunately true - mankind is left with a huge legacy of braindamaged code written in this language, since a great proportion of business software, particular accounting systems, is written in COBOL and has to be maintained.
There are a few projects to create OpenSource COBOL implementations, but it's a big and unrewarding task, especially since only a full-featured COBOL will be any good to anyone. After all, no one will start a new project in COBOL these days - its purpose would be for porting.