Editing Package manager (section)

===Challenges with shared libraries===
Computer systems that rely on [[dynamic library]] linking, instead of [[static library]] linking, share executable libraries of machine instructions across packages and applications. In these systems, conflicting relationships between different packages requiring different versions of libraries results in a challenge colloquially known as "[[dependency hell]]". On [[Microsoft Windows]] systems, this is also called "[[DLL hell]]" when working with dynamically linked libraries.<ref name="sharedlibrary">{{cite book |first= Chris |last= Tucker |title= 29th International Conference on Software Engineering (ICSE'07) |chapter= OPIUM: Optimal Package Install/Uninstall Manager |publisher= UC San Diego |date= 2007-03-15 |page=1 |doi=10.1109/ICSE.2007.59 |isbn= 978-0-7695-2828-1 |s2cid= 1279451 |url= https://escholarship.org/uc/item/1k07h5vk |chapter-url= http://cseweb.ucsd.edu/~lerner/papers/opium.pdf |archive-url=https://web.archive.org/web/20110614051810/http://cseweb.ucsd.edu/~lerner/papers/opium.pdf |archive-date=2011-06-14 |url-status=live |access-date= 2011-09-14}}</ref>

Modern package managers have mostly solved these problems, by allowing parallel installation of multiple versions of a library (e.g. [[OPENSTEP]]'s ''Framework'' system), a dependency of any kind (e.g. ''slots'' in Gentoo [[Portage (software)|Portage]]), and even of packages compiled with different compiler versions (e.g. dynamic libraries built by the [[Glasgow Haskell Compiler]], where a stable [[Application binary interface|ABI]] does not exist), in order to enable other packages to specify which version they were linked or even installed against.