Editing Open-source license (section)

===Compatibility===
{{main|License compatibility}}
[[File:Floss-license-slide-image.svg|alt=Chart of license compatibility, full details in section.|thumb|400px|Open-source software licenses and how they interact]]

[[License compatibility]] determines how code with different licenses can be distributed together. The goal of open-source licensing is to make the work freely available, but this becomes complicated when working with multiple terminologies imposing different requirements.{{sfn|Smith|2022|loc=sec.&nbsp;3.3}} There are many [[license proliferation|uncommonly used licenses]] and some projects write their own [[bespoke]] agreements. As a result, this causes more confusion than other legal aspects. When releasing a [[collective work|collection]] of applications, each license can be considered separately. However, when attempting to combine software, code from another project can only be in-licensed if the project uses compatible terms and conditions.{{sfn|Rosen|2005|pp=243-247}}

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 any 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=sec.&nbsp;3.3}} Permissive licenses are broadly compatible because they can cover separate parts of a project. Multiple licenses including the GPL and Apache License have been revised to enhance compatibility.<ref>See {{harvnb|Smith|2022|p=102}} for: Apache License version 2.0 in 2004, GPL version 3 in 2007, LGPL version 3 in 2007, and AGPL version 3 in 2007. See {{harvnb|Smith|2022|pp=95–101}} for: MPL version 2.0 in 2012 and EPL version 2 in 2017.</ref>

Translation issues, ambiguity in licensing terms, and incompatibility of some licenses with the law in certain jurisdictions compound the problem of license compatibility.{{sfn|Bernelin|2020|pp=100, 102}} Downloading an open-source module is straightforward, but complying with the licensing terms can be more difficult.{{sfn|Ombredanne|2020|p=105}} Because of the amount of software dependencies, engineers working on complex projects often rely on license management software to 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}}