CESIL is a high-level programming language developed in the early 1960s. It was designed for writing system software and was used by Digital Equipment Corporation (DEC) for this purpose. CESIL was also used by other companies, notably Honeywell and Burroughs, for developing system software.
CESIL is based on ALGOL 60 and has a number of features that make it well suited for system programming. These include a powerful macro facility, a rich set of data types, and support for multiple character sets.
CESIL was developed by a team led by David Gries and includes contributions from James Martin. It was originally known as DEC's System Implementation Language (SIL). The name CESIL was suggested by Martin and stands for "Common Environment for System Implementation Languages".
CESIL is no longer in use but it was an influential language in its time and helped to shape the development of other languages such as C and Pascal.