SQL was originally developed by Raymond F. Boyce and Donald D. Chamberlin at IBM in the early 1970s. The early version was originally called SEQUEL, standing for Structured English Query Language, and was designed to both manipulate and retrieve data stored in IBM’s original quasi-relational database management system, System R. The name SEQUEL was later changed to SQL. SQL was one of the first commercial languages for Edgar F. Codd’s relational model. It then became the most widely used database language despite it not completely adhering to the relational model described by Codd.