C is a general-purpose, block structured, procedural, imperative computer programming language for use with the Unix operating system. It has since spread to many other platforms. Although C was designed as a system implementation language, it is also widely used for applications. C has also greatly influenced many other popular languages, especially C++, which was originally designed as an extension to C. Its design goals were for it to be compiled using a relatively straightforward compiler, provide low-level access to memory, provide language constructs that map efficiently to machine instructions, and require minimal run-time support. C was therefore useful for many applications that had formerly been coded in assembly language. Despite its low-level capabilities, the language was designed to encourage machine-independent programming. A standards-compliant and portably written C program can be compiled for a very wide variety of computer platforms and operating systems with minimal change to its source code. The language has become available on a very wide range of platforms, from embedded microcontrollers to supercomputers.