C

C is a general-purpose, procedural programming language developed at Bell Labs by Dennis Ritchie, with early influence from BCPL and B, in the early 1970s to support the Unix operating system. It emphasizes efficiency, portability, and a small runtime, providing low-level access to memory through pointers while maintaining a high level of abstraction for data types and control structures. C quickly spread beyond Unix and became widely adopted in systems programming, embedded software, and applications requiring predictable performance.

Key features include static typing, a compiled toolchain, straightforward syntax using braces and semicolons, first-class functions via the function lexical scope, and a rich standard library. The language exposes memory management through pointers and explicit allocation and deallocation, which gives programmers fine-grained control but also requires care to avoid errors such as leaks, dangling references, and buffer overflows.

Standardization began with ANSI C (also referred to as C89/C90) in 1989 and ISO standards that followed. Subsequent revisions, including C99, C11, C17, and C23, added new features such as inline functions, complex numbers, improved thread support, and better Unicode handling, while preserving backward compatibility in most codebases.

C has profoundly influenced many later languages, notably C++, which extended and object-ifies the language, and informed other languages such as Java, C#, and Objective-C. It remains widely used in operating systems, compilers, embedded systems, and performance-critical applications, supported by a broad ecosystem of compilers, tools, and libraries.

Other meanings of the letter C exist, such as the Latin alphabet letter and the musical note; this article focuses on the programming language.