Subroutine package

A subroutine package (commonly called a library) is a group of subroutines which support some particular functionality.

On early machines which did not support floating point, it was common to have a floating point library. For commercial applications, which often use binary-coded decimal for arbitrary-precision numbers, a library implementing them was often provided on machines which lacked hardware support for BCD.

In the C programming language, which does not include I/O as part of the language, the Standard I/O Library is a portable way to peform I/O.