{"id":399,"date":"2025-12-10T21:55:33","date_gmt":"2025-12-10T21:55:33","guid":{"rendered":"https:\/\/abilit.eu\/?page_id=399"},"modified":"2025-12-15T07:05:41","modified_gmt":"2025-12-15T07:05:41","slug":"gpl-or-not-gpl","status":"publish","type":"page","link":"https:\/\/abilit.eu\/index.php\/gpl-or-not-gpl\/","title":{"rendered":"GPL or not GPL ?"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\"><em>What is GPL versus FreeSoftware ?<\/em><\/h2>\n\n\n\n<p><strong>Free Software<\/strong> is a category of software licenses as defined by the Free Software Foundation. You can find <a href=\"https:\/\/abilit.eu\/index.php\/free-software-freeware-freesoftware-public-domain-and-shareware\/\" data-type=\"page\" data-id=\"380\" target=\"_blank\" rel=\"noreferrer noopener\">explanation about it here<\/a>.<\/p>\n\n\n\n<p>The <strong><a href=\"https:\/\/www.gnu.org\/licenses\/gpl-3.0.en.html\" data-type=\"link\" data-id=\"https:\/\/www.gnu.org\/licenses\/gpl-3.0.en.html\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">GPL (General Public License)<\/a><\/strong> is one of the many software licenses that meet the requirements to be classified as a Free Software license.<\/p>\n\n\n\n<p>It is the license actively promoted by the <a href=\"https:\/\/www.gnu.org\" target=\"_blank\" rel=\"noreferrer noopener nofollow\"><strong>GNU organisation<\/strong><\/a>.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"433\" height=\"416\" src=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-10.png\" alt=\"\" class=\"wp-image-404\" style=\"border-width:1px\" srcset=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-10.png 433w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-10-300x288.png 300w\" sizes=\"auto, (max-width: 433px) 100vw, 433px\" \/><\/figure>\n\n\n\n<p style=\"padding-top:0;padding-bottom:0\">Its particularity is that it promotes the principle of <a href=\"https:\/\/www.gnu.org\/licenses\/copyleft.en.html\" data-type=\"link\" data-id=\"https:\/\/www.gnu.org\/licenses\/copyleft.en.html\" target=\"_blank\" rel=\"noreferrer noopener nofollow\"><strong>CopyLeft<\/strong><\/a>.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"512\" height=\"256\" src=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-8.png\" alt=\"\" class=\"wp-image-401\" style=\"border-width:1px\" srcset=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-8.png 512w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-8-300x150.png 300w\" sizes=\"auto, (max-width: 512px) 100vw, 512px\" \/><\/figure>\n\n\n\n<p style=\"padding-top:0;padding-bottom:0\">The <strong>Copyleft<\/strong> clause specifies that you cannot remove or change the GPL from GPL-licensed source code. The goal is to extend the GPL license across the entire Free Software ecosystem through a process often called &#8220;contagion&#8221;: if you obtain software (and thus its source code) under the GPL, you must distribute it\u2014and any derivative works\u2014under the GPL as well.<\/p>\n\n\n\n<p>If you link a GPL-licensed program with other software (using a <a href=\"https:\/\/en.wikipedia.org\/wiki\/Linker_(computing)\" data-type=\"link\" data-id=\"https:\/\/en.wikipedia.org\/wiki\/Linker_(computing)\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">linker<\/a>), the other software must also be licensed under terms compatible with the GPL. As a result, the combined work can only be distributed under the GPL. In this way, the GPL progressively encourages more software (and its source code) to be released under its terms, which is precisely its intended purpose.<\/p>\n\n\n\n<p>An example of this principle can be found in <em>&#8220;<a href=\"https:\/\/www.gnu.org\/philosophy\/pragmatic.en.html\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Copyleft: Pragmatic Idealism<\/a>&#8220;<\/em> by <strong><a href=\"https:\/\/www.stallman.org\/\" data-type=\"link\" data-id=\"https:\/\/www.stallman.org\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">RIchard Stallman<\/a><\/strong>.<\/p>\n\n\n\n<p style=\"border-width:1px;padding-top:var(--wp--preset--spacing--10);padding-right:var(--wp--preset--spacing--10);padding-bottom:var(--wp--preset--spacing--10);padding-left:var(--wp--preset--spacing--10)\"><em>Consider GNU C++. Why do we have a free C++ compiler? Only because the GNU GPL said it had to be free. GNU C++ was developed by an industry consortium, MCC, starting from the GNU C compiler. MCC normally makes its work as proprietary as can be. But they made the C++ front end free software, because the GNU GPL said that was the only way they could release it. The C++ front end included many new files, but since they were meant to be linked with GCC, the GPL did apply to them. The benefit to our community is evident.<\/em><br><br><em>Consider GNU Objective C. NeXT initially wanted to make this front end proprietary; they proposed to release it as .o files, and let users link them with the rest of GCC, thinking this might be a way around the GPL&#8217;s requirements. But our lawyer said that this would not evade the requirements, that it was not allowed. And so they made the Objective C front end free software.<\/em><br><em><br>Those examples happened years ago, but the GNU GPL continues to bring us more free software.<\/em><\/p>\n\n\n\n<p>The <strong><a href=\"https:\/\/www.kernel.org\/\" data-type=\"link\" data-id=\"https:\/\/www.kernel.org\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Linux kernel<\/a><\/strong> is released under the <strong>GPL license<\/strong>.<\/p>\n\n\n\n<p>Similarly, the <strong>GNU ecosystem<\/strong>, when combined with the Linux kernel, forms the <strong><strong><a href=\"https:\/\/www.gnu.org\/gnu\/linux-and-gnu.en.html\" data-type=\"link\" data-id=\"https:\/\/www.gnu.org\/gnu\/linux-and-gnu.en.html\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">GNU\/Linux Operating System<\/a><\/strong><\/strong>: a complete operating system that includes libraries, real-time support, preemptive multitasking, native virtualisation, virtual memory management, logical volumes, distributed and journaling file systems, software RAID, a network stack, graphical user interfaces (GUIs), compilers, debuggers, and more. The entire system is licensed under the GPL, making it <strong><strong><a href=\"https:\/\/abilit.eu\/index.php\/free-software-freeware-freesoftware-public-domain-and-shareware\/\" data-type=\"page\" data-id=\"380\" target=\"_blank\" rel=\"noreferrer noopener\">FreeSoftware<\/a><\/strong><\/strong>. It is <a href=\"https:\/\/bfrere.world\/WITMUOSITW.pdf\" data-type=\"link\" data-id=\"https:\/\/bfrere.world\/WITMUOSITW.pdf\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">widely supported and used<\/a> by both the community and major corporations (such as <a href=\"https:\/\/www.ibm.com\/products\/z\/linux\" data-type=\"link\" data-id=\"https:\/\/www.ibm.com\/products\/z\/linux\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">IBM<\/a>, <a href=\"https:\/\/consumer.huawei.com\/ph\/community\/details\/topicId-145216\/\" data-type=\"link\" data-id=\"https:\/\/consumer.huawei.com\/ph\/community\/details\/topicId-145216\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Huawei<\/a>, <a href=\"https:\/\/i.dell.com\/sites\/content\/business\/solutions\/operating-systems\/en\/Documents\/novell-unix-to-linux.pdf\" data-type=\"link\" data-id=\"https:\/\/i.dell.com\/sites\/content\/business\/solutions\/operating-systems\/en\/Documents\/novell-business-value.pdf\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Novell<\/a>, Intel, <a href=\"https:\/\/www.servethehome.com\/nvidia-open-sources-gpu-drivers-for-linux\/\" data-type=\"link\" data-id=\"https:\/\/www.servethehome.com\/nvidia-open-sources-gpu-drivers-for-linux\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">NVidia<\/a>, <a href=\"https:\/\/aws.amazon.com\/fr\/amazon-linux-2\/\" data-type=\"link\" data-id=\"https:\/\/aws.amazon.com\/fr\/amazon-linux-2\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Amazon<\/a>, Google, <a href=\"https:\/\/itsfoss.com\/news\/google-sos-sponsor\/\" data-type=\"link\" data-id=\"https:\/\/itsfoss.com\/news\/google-sos-sponsor\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Google<\/a>, and even <a href=\"https:\/\/www.linuxfoundation.org\/press\/press-release\/microsoft-fortifies-commitment-to-open-source-becomes-linux-foundation-platinum-member\" data-type=\"link\" data-id=\"https:\/\/www.linuxfoundation.org\/press\/press-release\/microsoft-fortifies-commitment-to-open-source-becomes-linux-foundation-platinum-member\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Microsoft<\/a>), ensuring its <strong>long-term sustainability.<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"716\" src=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-18-1024x716.png\" alt=\"\" class=\"wp-image-421\" style=\"border-width:1px\" srcset=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-18-1024x716.png 1024w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-18-300x210.png 300w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-18-768x537.png 768w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-18.png 1152w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><strong>GNU\/Linux is the operating system powering 100% of the world\u2019s top 500 most powerful computer systems<\/strong> (as of November 2017), according to data from <a href=\"https:\/\/www.top500.org\" target=\"_blank\" rel=\"noreferrer noopener\">top500.org<\/a>:<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"668\" src=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-15-1024x668.png\" alt=\"\" class=\"wp-image-415\" style=\"border-width:1px\" srcset=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-15-1024x668.png 1024w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-15-300x196.png 300w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-15-768x501.png 768w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-15.png 1158w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p class=\"has-text-align-center\"><em>OS Family Share in the Top 500 Supercomputers Worldwide<\/em><br>(source: <a href=\"https:\/\/top500.org\/statistics\/overtime\/\" data-type=\"link\" data-id=\"https:\/\/top500.org\/statistics\/overtime\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">top500.org<\/a>)<\/p>\n\n\n\n<p><strong>MacOS<\/strong> once reached a peak of <strong>5 out of 500 (1%)<\/strong> around 2005.<br>Here is the zoomed view of the previous picture:<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"388\" src=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-16-1024x388.png\" alt=\"\" class=\"wp-image-417\" style=\"border-width:1px\" srcset=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-16-1024x388.png 1024w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-16-300x114.png 300w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-16-768x291.png 768w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-16.png 1360w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><strong>Windows<\/strong> peaked at <strong>4 out of 500<\/strong> around 2008. Here is the zoomed view:<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"821\" src=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-17-1024x821.png\" alt=\"\" class=\"wp-image-418\" style=\"border-width:1px\" srcset=\"https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-17-1024x821.png 1024w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-17-300x241.png 300w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-17-768x616.png 768w, https:\/\/abilit.eu\/wp-content\/uploads\/2025\/12\/image-17.png 1115w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>The conclusion is clear: when it comes to specifying, designing, and deploying <strong>highly professional, powerful, strategic, and industrial-grade computing systems<\/strong>, there is only one choice: <strong>Unix\/Linux<\/strong> (the distinction between the two is minimal in this context). These systems are not built on small-scale, unreliable operating systems designed for gaming, video editing, or visually appealing desktop interfaces.<\/p>\n\n\n\n<p class=\"has-text-align-center has-large-font-size\"><em><strong><strong>When serious work is at stake,<\/strong><\/strong><br><strong><strong>a professional-grade operating system<\/strong><\/strong><br><strong><strong>is essential.<\/strong><\/strong><\/em><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><em><strong>Evolution of the GPL<\/strong><\/em><\/h2>\n\n\n\n<p>As threats to Free Software and software user rights have evolved over time, so has the GPL. The current version is <strong>GPL 3.0<\/strong>, which is compatible with earlier versions. However, software licensed under a specific GPL version <strong>cannot revert to a previous version<\/strong>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><em>Advantages of the GPL<\/em><\/h2>\n\n\n\n<p>When a company like <strong>Abil&#8217;I.T<\/strong> offers GPL-licensed software, it typically falls into one of two categories:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The company <strong>fully owns the source code<\/strong> (e.g., MySQL, OpenOffice).<br><\/li>\n\n\n\n<li>The company <strong>acquired the source code under the GPL<\/strong> (e.g., Scada-LTS, based on a GPL-licensed version of Scada-BR).<\/li>\n<\/ul>\n\n\n\n<p>Why does this distinction matter ?<\/p>\n\n\n\n<p>It is <strong>critical for end users<\/strong>. A company that fully owns the source code from the outset can, at any time, <strong>close the source code<\/strong>, forcing users into a <strong><a href=\"https:\/\/en.wikipedia.org\/wiki\/Vendor_lock-in\" data-type=\"link\" data-id=\"https:\/\/en.wikipedia.org\/wiki\/Vendor_lock-in\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">proprietary software lock-in<\/a><\/strong>. This is a <strong>real risk<\/strong>: one that should never be accepted, especially if the software is a <strong>key resource<\/strong> for <strong>managing strategic assets<\/strong>.<\/p>\n\n\n\n<p>On the other hand, a company like <strong>Abil&#8217;I.T<\/strong>, which obtained the base source code under the GPL, <strong>cannot legally close the source code<\/strong>. Users are <strong>guaranteed access<\/strong> to it at all times, retaining all the rights of Free Software, including:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><strong>No usage restrictions<\/strong><\/strong> (amount of concurrent user sessions, screens, &#8230;)<\/li>\n\n\n\n<li><strong>No data processing limits<\/strong> (unlimited datasources, storage, &#8230;)<\/li>\n\n\n\n<li><strong>No hardware restrictions<\/strong> (e.g., CPUs, cores, RAM, storage, &#8230;)<\/li>\n\n\n\n<li><strong>No geographical or political restrictions<\/strong> (e.g., no bans on &#8220;sensitive&#8221; technologies or military applications, &#8230;)<\/li>\n\n\n\n<li><strong>Full rights to modify or correct any part of the software<\/strong><\/li>\n\n\n\n<li><strong>Full rights to add new functionalities<\/strong> (make it evolve to match your new needs, &#8230;)<\/li>\n<\/ul>\n\n\n\n<p>Basically, <strong>no restriction at all<\/strong> but the one that says that&#8230;<\/p>\n\n\n\n<p class=\"has-text-align-center has-large-font-size\"><strong><em>If you distribute the software <\/em><\/strong><br>(<strong><em>or any modified version<\/em><\/strong>)<br><strong><em>you must do so<\/em><\/strong><br><strong><em>under <span style=\"text-decoration: underline;\">the GPL license terms<\/span>.<\/em><\/strong><\/p>\n\n\n\n<p><strong>Why the GPL Matters<\/strong><\/p>\n\n\n\n<p>The GPL ensures the <strong>long-term sustainability<\/strong> of your software solution, regardless of what happens to the original developer. Because you <strong>own the source code<\/strong> <strong>and the right to maintain it<\/strong>, you are protected from <a href=\"https:\/\/en.wikipedia.org\/wiki\/Vendor_lock-in\" data-type=\"link\" data-id=\"https:\/\/en.wikipedia.org\/wiki\/Vendor_lock-in\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">vendor lock-in<\/a>.<\/p>\n\n\n\n<p>As a <strong>Free Software-compatible license<\/strong>, the GPL grants you <strong>unrestricted rights<\/strong> to use the software for any purpose, forever.<\/p>\n\n\n\n<p><strong>This is why and how we develop Scada-LTS:<\/strong> as a <strong>perfect example<\/strong> of sustainable, user-controlled software. Abil&#8217;I.T. is commited to<\/p>\n\n\n\n<p class=\"has-text-align-center has-large-font-size\"><em><strong>sustainable software <\/strong><br><strong>for a sustainable world.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>What is GPL versus FreeSoftware ? Free Software is a category of software licenses as defined by the Free Software Foundation. You can find explanation about it here. The GPL (General Public License) is one of the many software licenses that meet the requirements to be classified as a Free Software license. It is the [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-399","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/abilit.eu\/index.php\/wp-json\/wp\/v2\/pages\/399","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/abilit.eu\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/abilit.eu\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/abilit.eu\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/abilit.eu\/index.php\/wp-json\/wp\/v2\/comments?post=399"}],"version-history":[{"count":15,"href":"https:\/\/abilit.eu\/index.php\/wp-json\/wp\/v2\/pages\/399\/revisions"}],"predecessor-version":[{"id":451,"href":"https:\/\/abilit.eu\/index.php\/wp-json\/wp\/v2\/pages\/399\/revisions\/451"}],"wp:attachment":[{"href":"https:\/\/abilit.eu\/index.php\/wp-json\/wp\/v2\/media?parent=399"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}