Precompiled

Precompiled refers to the practice of producing a finished form of data, code, or resources before runtime, so it can be used directly or more efficiently by a program. In software development, precompilation typically means translating source code into machine code or into a binary representation that a runtime environment can load quickly. It can also apply to resources, templates, or headers that are processed once and reused thereafter.

There are several common forms of precompilation. Precompiled code is created by an ahead-of-time compiler and yields executables or libraries that do not require further translation before execution. This contrasts with interpreted code, where source is executed directly, and with just-in-time compilation, which compiles while the program is running. Precompiled content can speed startup, reduce CPU load during first runs, and improve deployment consistency.

Precompiled headers are a related technique primarily used in C and C++ development. A precompiled header gathers frequently used system or project headers into a single precompiled unit, reducing repetitive parsing time during compilation. This speeds up build processes but introduces cache invalidation and portability considerations when headers change or differ between environments.

Precompiled libraries and binaries are widely distributed so users can install and link software without recompiling. Static libraries, dynamic libraries, and platform-specific binaries are common forms. Package managers and build systems frequently offer precompiled packages to save time, though they may require recompilation for optimization, security updates, or cross-platform compatibility.

Benefits of precompilation include faster startup, shorter build times, and easier distribution. Limitations include reduced flexibility, potential portability issues, and the need to recompile when target environments change or software is updated.