Editing Shared library (section)

==Dynamic linking==
{{main|Dynamic linker}}

Dynamic linking or [[late binding]] is linking performed while a program is being loaded ([[load time]]) or executed ([[Runtime (program lifecycle phase)|runtime]]), rather than when the executable file is created. A dynamically linked library ([[dynamic-link library]], or DLL, under [[Microsoft Windows|Windows]] and [[OS/2]]; shareable image under [[OpenVMS]];<ref>{{cite web|url=https://vmssoftware.com/docs/VSI_Linker_Manual.pdf|title=VSI OpenVMS Linker Utility Manual|date=August 2019|access-date=2021-01-31|publisher=VSI}}</ref> dynamic shared object, or DSO, under [[Unix-like]] systems) is a library intended for dynamic linking. Only a minimal amount of work is done by the [[Linker (computing)|linker]] when the executable file is created; it only records what library routines the program needs and the index names or numbers of the routines in the library. The majority of the work of linking is done at the time the application is loaded (load time) or during execution (runtime). Usually, the necessary linking program, called a ''dynamic linker'' or ''linking loader'', is actually part of the underlying [[operating system]]. (However, it is possible, and not exceedingly difficult, to write a program that uses dynamic linking and includes its own dynamic linker, even for an operating system that itself provides no support for dynamic linking.)

Programmers originally developed dynamic linking in the [[Multics]] operating system, starting in 1964, and the MTS ([[Michigan Terminal System]]), built in the late 1960s.<ref>{{cite journal | title=A History of MTS | journal=Information Technology Digest | volume=5 | issue=5}}</ref>