{"id":787,"date":"2005-11-28T22:13:00","date_gmt":"2005-11-28T16:43:00","guid":{"rendered":"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/28\/gnu-general-public-license-share-and-change-free-software\/"},"modified":"2026-10-12T18:59:06","modified_gmt":"2026-10-12T13:29:06","slug":"gnu-general-public-license-share-and-change-free-software","status":"publish","type":"post","link":"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/","title":{"rendered":"GNU General Public License (GPL) Explained in Plain English (2026)"},"content":{"rendered":"<p>The <strong>GNU General Public License<\/strong> (GPL) is one of the most important software licenses ever written. It guarantees your freedom to use, share and change free software, and it powers projects like Linux and WordPress, which runs this site. When we first wrote about it in 2005, open source was still niche. Here&#8217;s what the GPL means in 2026, in plain English. (This is a general overview, not legal advice.)<\/p>\n<p><img decoding=\"async\" class=\"aligncenter size-large wp-image-64749\" src=\"https:\/\/www.quickonlinetips.com\/archives\/wp-content\/uploads\/gnu-general-public-license-1024x538.webp\" alt=\"GNU General Public License explained\" width=\"1024\" height=\"538\" srcset=\"https:\/\/www.quickonlinetips.com\/archives\/wp-content\/uploads\/gnu-general-public-license-1024x538.webp 1024w, https:\/\/www.quickonlinetips.com\/archives\/wp-content\/uploads\/gnu-general-public-license-300x158.webp 300w, https:\/\/www.quickonlinetips.com\/archives\/wp-content\/uploads\/gnu-general-public-license-150x79.webp 150w, https:\/\/www.quickonlinetips.com\/archives\/wp-content\/uploads\/gnu-general-public-license-768x403.webp 768w, https:\/\/www.quickonlinetips.com\/archives\/wp-content\/uploads\/gnu-general-public-license.webp 1200w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/p>\n<p><strong>Quick answer:<\/strong> The GPL is a free software license from the Free Software Foundation. Anyone may run, study, share and modify GPL software, even commercially. The catch is &#8220;copyleft&#8221;: if you distribute a modified version, you must release it under the GPL too and provide the source code. The two common versions are GPLv2 (used by Linux and WordPress) and GPLv3 (adds patent and anti-lockdown terms).<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_89 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6ae97e98daff3\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"ez-toc-cssicon\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #1a202c;color:#1a202c\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #1a202c;color:#1a202c\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6ae97e98daff3\" checked aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#The_four_freedoms\" >The four freedoms<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#What_copyleft_means\" >What copyleft means<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#GPLv2_vs_GPLv3\" >GPLv2 vs GPLv3<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#What_you_can_and_cant_do\" >What you can and can&#8217;t do<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#Why_WordPress_themes_and_plugins_are_GPL\" >Why WordPress themes and plugins are GPL<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#FAQ\" >FAQ<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#Is_GPL_software_free_of_charge\" >Is GPL software free of charge?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#Can_I_use_GPL_code_in_a_commercial_app\" >Can I use GPL code in a commercial app?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.quickonlinetips.com\/archives\/2005\/11\/gnu-general-public-license-share-and-change-free-software\/#Whats_the_difference_between_GPL_and_MIT_licences\" >What&#8217;s the difference between GPL and MIT licences?<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"The_four_freedoms\"><\/span>The four freedoms<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ol>\n<li>Run the program for any purpose.<\/li>\n<li>Study how it works and change it (requires access to the source code).<\/li>\n<li>Redistribute copies.<\/li>\n<li>Distribute your modified versions.<\/li>\n<\/ol>\n<h2><span class=\"ez-toc-section\" id=\"What_copyleft_means\"><\/span>What copyleft means<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Copyleft uses copyright law to keep software free. If you share a modified GPL program, the recipients get the same freedoms you had. You can&#8217;t take GPL code, change it and release it as closed source.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"GPLv2_vs_GPLv3\"><\/span>GPLv2 vs GPLv3<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><strong>GPLv2 (1991):<\/strong> used by the Linux kernel and WordPress (&#8220;GPLv2 or later&#8221;).<\/li>\n<li><strong>GPLv3 (2007):<\/strong> adds explicit patent licences, compatibility with more licences and rules against &#8220;tivoisation&#8221; (hardware that blocks modified software).<\/li>\n<li><strong>LGPL:<\/strong> a weaker variant that lets non-GPL programs link to a library.<\/li>\n<li><strong>AGPL:<\/strong> extends copyleft to software used over a network, like web apps.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"What_you_can_and_cant_do\"><\/span>What you can and can&#8217;t do<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><strong>Can:<\/strong> use GPL software in your business, charge for distribution or support, modify it for private use without sharing.<\/li>\n<li><strong>Must:<\/strong> include the licence and provide source code when you distribute binaries.<\/li>\n<li><strong>Can&#8217;t:<\/strong> add restrictions that take away users&#8217; freedoms.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Why_WordPress_themes_and_plugins_are_GPL\"><\/span>Why WordPress themes and plugins are GPL<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>WordPress is GPLv2 or later, and the WordPress project considers themes and plugins that build on it to be GPL too. That&#8217;s why premium plugins still ship under the GPL; buyers pay for updates and support. See our list of <a href=\"https:\/\/www.quickonlinetips.com\/archives\/2009\/06\/open-source-windows-applications\/\">open source applications for Windows<\/a> for more GPL software.<\/p>\n<p>Read the full text on the <a href=\"https:\/\/www.gnu.org\/licenses\/gpl-3.0.html\" rel=\"noopener\" target=\"_blank\">GNU website<\/a>, along with the <a href=\"https:\/\/www.gnu.org\/licenses\/license-list.html\" rel=\"noopener\" target=\"_blank\">list of free software licences<\/a>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"FAQ\"><\/span>FAQ<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Is_GPL_software_free_of_charge\"><\/span>Is GPL software free of charge?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Usually, but &#8220;free&#8221; means freedom. You may sell GPL software as long as buyers get the same freedoms.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Can_I_use_GPL_code_in_a_commercial_app\"><\/span>Can I use GPL code in a commercial app?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Yes, but if you distribute the app, the combined work generally must be GPL too.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Whats_the_difference_between_GPL_and_MIT_licences\"><\/span>What&#8217;s the difference between GPL and MIT licences?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>MIT is permissive: you can use the code in closed-source products. GPL requires derivative works to stay open.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The GNU General Public License (GPL) is one of the most important software licenses ever written. It guarantees your freedom&#8230;<\/p>\n","protected":false},"author":4,"featured_media":64749,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-787","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tips"],"_links":{"self":[{"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/posts\/787","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/comments?post=787"}],"version-history":[{"count":1,"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/posts\/787\/revisions"}],"predecessor-version":[{"id":64750,"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/posts\/787\/revisions\/64750"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/media\/64749"}],"wp:attachment":[{"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/media?parent=787"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/categories?post=787"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.quickonlinetips.com\/archives\/wp-json\/wp\/v2\/tags?post=787"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}