Editing GPL linking exception (section)

{{Short description|License exception of GNU General Public License}}
A '''GPL linking exception''' modifies the [[GNU General Public License]] (GPL) in a way that enables software projects which provide [[Library (computing)|library]] code to be "[[Linker (computing)|linked to]]" the programs that use them, without applying the full terms of the GPL to the using program. Linking is the technical process of connecting code in a library to the using code, to produce a single [[executable|executable file]]. It is performed either at [[compile time]] or [[Run time (program lifecycle phase)|run-time]] in order to produce functional machine-readable code. The Free Software Foundation states that, without applying the ''linking exception'', a program linked to GPL library code may only be distributed under a GPL-compatible license.<ref>{{cite web
|title       = GPL FAQ - Linking With GPL
|url         = https://www.gnu.org/licenses/gpl-faq.html#LinkingWithGPL
}}</ref> This has not been explicitly tested in court, but linking violations have resulted in settlement.<ref>{{cite web | url=https://www.theregister.com/2002/11/21/mysql_nusphere_settle_gpl_contract/ | title=MySQL, NuSphere Settle GPL Contract Dispute | access-date=20 May 2021}}</ref> The license of the [[#The Classpath exception|GNU Classpath]] project explicitly includes a statement to that effect.

Many free software libraries which are distributed under the GPL use an equivalent exception, although the wording of the exception varies. Notable projects include [[ERIKA Enterprise]],<ref>{{cite web |url=http://wiki.automotive.linuxfoundation.org/index.php/Erika_Enterprise_Open-Source_RTOS |title=Erika Enterprise Open-Source RTOS |work=[[Linux Foundation]]}}</ref> [[GNU Guile]],<ref name="license-list">Stallman, Richard. [https://www.gnu.org/philosophy/license-list.html Various Licenses and Comments about Them] {{webarchive |url=https://web.archive.org/web/20000815065020/http://www.gnu.org/philosophy/license-list.html |date=August 15, 2000 }}. Free Software Foundation. Published on 2007-05-17. Retrieved on 2007-05-18.</ref> the run-time libraries of [[GNAT]],<ref name="license-list" /> [[GNU Classpath]]<ref name="classpathlicense">[https://www.gnu.org/software/classpath/license.html Classpath::License]. Free Software Foundation. 2007-04-23. Retrieved on 2007-05-18.</ref> and the [[GCC Runtime Library Exception]].<ref name="gccruntimelibraryexception">[https://www.gnu.org/licenses/gcc-exception.html GCC Runtime Library Exception]. Free Software Foundation. 2009-03-31. Retrieved on 2011-10-18.</ref>

Compiler runtime libraries also often use this license modification or an equivalent one, e.g. the <code>libgcc</code> library in the [[GNU Compiler Collection]],<ref>[https://archive.today/20120708181428/http://gcc.gnu.org/viewcvs/trunk/gcc/libgcc2.c?revision=152139&view=markup Text of the GCC license] gcc code repository. 2009-09-24. Retrieved on 2010-01-19.</ref> as well as all libraries of the [[Free Pascal]] project.

In 2007, Sun Microsystems released most of the [[source code]] to the [[class library|class libraries]] for the [[Java Platform, Standard Edition|Java SE]] and [[Java Platform, Enterprise Edition|Java EE]] projects under version 2 of the GPL license plus the Classpath linking exception,<ref>{{cite web
| url=http://www.sun.com/software/opensource/java/project_overview.jsp
| title= Open-Source Java Project Overview
| publisher=[[Sun Microsystems]]
| access-date=2007-05-22}}</ref> and used the same license as one possible license for their enterprise server [[GlassFish]]<ref name="glassfishlicense">{{cite web
|url        = https://glassfish.dev.java.net/public/CDDL+GPL.html
|archive-url = https://wayback.archive-it.org/all/20160117093912/https://glassfish.java.net/public/CDDL+GPL.html
|url-status = dead
|archive-date = 2016-01-17
|title        = Glassfish license
|date        = 2008-03-27
|access-date        = 2008-03-27
}}</ref> and for their [[NetBeans]] Java [[Integrated development environment|IDE]].<ref name="netbeanslicense">[http://www.netbeans.org/about/legal/license.html Netbeans license] {{Webarchive|url=https://web.archive.org/web/20060713050255/http://www.netbeans.org/about/legal/license.html |date=2006-07-13 }}. 2008-03-27. Retrieved on 2008-03-27.</ref>

Version 3 of the [[GNU Lesser General Public License]] (LGPL)<ref>[https://www.gnu.org/licenses/lgpl.html GNU Lesser General Public License, Version 3]. 2007-06-29. Retrieved on 2007-10-19.</ref> is likewise constructed as an exception to the GPL.<ref>[http://gplv3.fsf.org/lgpl3-dd2-guide Guide to the second draft of LGPLv3]. 2007-04-03. Retrieved on 2007-05-10.</ref>