runtime library

A collection of executable software functions in the machine language of the target computer. A runtime library can be linked into an application at compile time with links already resolved from the programmer's code to the functions when the application is loaded. With this "static" linking, the runtime routines become part of the executable application.

Runtime routines can also reside in external files that are called for and dynamically linked to from the application at runtime. Dynamic link libraries (DLLs) are a common example. Development environments may provide both methods; for example, the C runtime (CRT) library, which provides the routines for standard C functions, provides both static and dynamic runtime capabilities. See DLL, runtime and runtime version.