Editing Software license (section)

===Compatibility===
{{see also|License compatibility}}
[[File:GPL-Compatible.svg|thumb|upright=1.5|Compatibility chart for some open-source software licenses]]
Since 1989,{{sfn|Bernelin|2020|p=96}} a variety of [[open-source license]]s for software have been created.{{sfn|Sen|Subramaniam|Nelson|2008|p=208}} Choosing an open-source software license has grown increasingly difficult due to the [[license proliferation|proliferation of licenses]],{{sfn|Alamoudi ''et al.''|2020|p=537}}{{sfn|Bernelin|2020|p=94}} many of which are only trivially distinct.{{sfn|Morin ''et al.''|2012|loc=Compatibility, Proliferation, Fragmentation, and Directionality}} Many licenses are incompatible with each other, hampering the goals of the free software movement.{{sfn|Bernelin|2020|p=98}} Translation issues, ambiguity in licensing terms, and incompatibility of some licenses with the law in certain jurisdictions compounds the problem.{{sfn|Bernelin|2020|pp=100, 102}} 

Although downloading an open-source module is quick and easy, complying with the licensing terms can be more difficult.{{sfn|Ombredanne|2020|p=105}} The amount of software dependencies means that engineers working on complex projects must often rely on software license management software in order to help them achieve compliance with the licensing terms of open-source components.{{sfn|Ombredanne|2020|p=106}} Many open-source software files do not unambiguously state the license, increasing the difficulties of compliance.{{sfn|Ombredanne|2020|p=105}} When combining code bases, the original licenses can be maintained for separate components, and the larger work released under a compatible license.{{sfn|St. Laurent|2004|pp=159-163}} This compatibility is often one-way. Public domain content can be used anywhere as there is no copyright claim, but code acquired under almost any set of terms cannot be waved to the public domain. Permissive licenses can be used within copyleft works, but copyleft material cannot be released under a permissive license. Some weak copyleft licenses can be used under the GPL and are said to be GPL-compatible. GPL software can only be used under the GPL or AGPL.{{sfn|Smith|2022|loc=§&nbsp;3.3}}