CS-4[1] is a programming language and an operating system interface. It was developed in the early 1970s at Intermetrics in Cambridge, Massachusetts. The first published manual was released in December 1973, entitled "CS-4 Language Reference Manual and Operating System Interface".[1] The document had three parts: CS-4 Base Language Capabilities; CS-4 Operating System Interface; and Overview of Full CS-4 Capabilities.
Little is known about the CS-4 language, but it was developed for the United States Navy in the 1970s, and was an ongoing research project, which was continuing the study of extensibility and abstraction techniques to develop a requirement of the language to be simple and compact.[4] The language was first documented in 1973 by Miller et al.,[4] and was revised in 1975 to allow "data abstractions and more powerful extension facilities".[4]