POSIX

POSIX, an acronym for Portable Operating System Interface, is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. It was developed to ensure that software written for one POSIX-compliant system can be run on another with minimal or no modification. The standards are maintained by the Austin Group, a collaboration of technical experts from various organizations.

The POSIX standards define the application programming interface (API), command line shells and utility interfaces, and other aspects of the operating system. They cover a wide range of functionalities, including file system operations, process control, inter-process communication, and more. The standards are designed to be flexible and extensible, allowing for the addition of new features without breaking compatibility with existing software.

POSIX is widely adopted in the Unix and Unix-like operating systems, including Linux, macOS, and various distributions of BSD. It has also influenced the development of other operating systems, such as Windows Subsystem for Linux (WSL), which provides a compatibility layer for running Linux binaries on Windows.

The POSIX standards are regularly updated to keep pace with the evolving needs of software developers and the changing landscape of computing. The most recent version, POSIX.1-2017, includes updates to the base specifications, as well as new standards for threads, real-time extensions, and more.