compat

In computing, compat (short for compatibility) refers to the ability of software, hardware, or data to work together or with other systems. Compatibility is achieved through standards, interfaces, and implementations that allow programs or devices to interoperate across versions, platforms, or generations.

Common forms include source compatibility (code can be compiled on different platforms), binary compatibility (compiled executables run on other systems without recompilation), and ABI compatibility (how functions are called at runtime). Data compatibility concerns file formats and encoding.

Practices to improve compat include compatibility layers, emulation, wrappers or shim libraries, and maintaining deprecated interfaces for a period. In operating systems, compatibility packages provide libraries or stubs to run legacy software—examples include 32-bit compatibility libraries on 64-bit systems, or Windows compatibility modes.

In software development, API compatibility ensures programs relying on an interface continue to work after updates; semantic versioning helps communicate breaking changes. Standards bodies define protocols and formats to promote interoperability.

The term compat is also used in specific project names or packages, such as libraries named compat in Linux distributions, or FreeBSD's compat libraries that enable older binaries or different CPU ABIs.