Daytoday development discussions take place on the linux kernel mailing list lkml. Heres an article by richard stallman himself emphasis mine. General public license lgpl are widelyused open source software licenses. Enforcing the gnu gpl gnu project free software foundation. While discussing gplv3, some people have suggested that even when version 3 of the gpl is released, the linux kernel developers will not have the option of using it due to reasons this is incorrect, but it is based on a real problem. Although the gpl covers the linux kernel, the gpl doesnt cover your applications that use the kernel services through system calls. The gnu general public license gnu gpl or gpl is a series of widely used free software licenses that guarantee end users the freedom to run, study, share, and modify the software. This is the same license the linux kernel is under, so you may be somewhat familiar with it by now. Thus, the gpl license, which allows grsecurity to create its derivative work of the linux kernel, terminates, and the of the linux kernel is infringed. The core component of the linux operating system is. Greg kroahhartman, linux kernel maintainer and fellow at the linux foundation. The kernel is built with apis for the attachment of moduleswhich in a user space program might be called pluginswhich can be statically linked with the kernel or dynamically loaded into kernel space by a running kernel. Plenty of commercial software is available for linux, and it.
Understanding the license that governs linux novell. The gnu general public license gpl version 1 should not be used in new. Friendlier gplenforcement permission proposed by linux. Android uses linux as its kernel, but does not include gnu software, and includes proprietary software on top, which make it very different from the desktop gnulinux distributions.
Both companies use the linux kernel, which is licensed under the gnu general public license, version 2 gnu gpl. The adversaries in the case are the manufacturer and distributor of dsl routers avm computersysteme vertriebs gmbh avm, and cybits ag cybits which produces childrens webfiltering software. What drove linus torvalds to create linux, the open source kernel that. As with any such interface in a gplv2 program running outside kernel space. In a message to the linux kernel mailing list on jan. If you plan to distribute your application in binary form as most commercial software is distributed, you must make sure that your application doesnt use any parts of any software the gpl covers. Software freedom conservancy, home of the gpl compliance project for linux developers, publicly applauded today the proposal of the linux kernel enforcement statement, which adds a per. Plenty of commercial software is available for linux, and it does not violate the gpl in any way. The gpl doesnt ask for you to provide source code for derivative works, it asks you to license them under the gpl. The text of the gnu general public license gpl is in a file named copying in various directories in your linux system. Licensing and using the linux kernel stack overflow. Legal risks of open source gpllinux loadable kernel.
Most people may not care but the difference in licensing is actually significant. The license agreements of most software companies try to keep users. Practical gpl compliance is a guide for startups, small businesses. Prominent freesoftware programs licensed under the gpl include the linux kernel and the gnu compiler collection gcc. They would further argue that their user code runs on several kernels and is not dependent on the linux kernel in. And because no one can ever redistribute without a license, we can safely presume that anyone redistributing gpld software intended to accept the gpl. Therefore, the gpled linux kernel can link against your closedsource driver without any problems. A complete copy of the license text is included in the file license in the busybox source code. When viewing the version number for a linux kernel, what number indicates the. Gpl section 6 specifically prohibits any addition of terms. Busybox is licensed under the gnu general public license version 2, which is often abbreviated as gplv2. Linuxs overall license of the kernel is gplv2 only. Search a portfolio of license management software, saas and cloud applications for linux.
Prominent free software programs licensed under the gpl include the linux kernel and the gnu compiler collection gcc. Plus, the open source parts of android are licensed under the apache 2. The gnu general public license gpl was developed by which organization. You can run android, and the other permissive software, on linux the same way you can use nvidias proprietary driver on your regular pc. The licenses were originally written by richard stallman, former head of the free software foundation fsf, for the gnu project, and grant the recipients of a computer program the rights of the free software definition. Linux, the kernel at the heart of an operating system that clones much of generally proprietary unix, is considered.
Linux kernel licensing rules the linux kernel documentation. Can i link to a gpl library from a closed source application. Despite the critical role the gpl plays in the advance of linux, not many people understand its terms. Aside from that, individual files can be provided under a dual license, e. As with similar activities conducted by the fsf free software foundation, the sfcs goal is to see breaches of the terms of the gpl cured and the full source code the license requires made. Contribute to torvaldslinux development by creating an account on github. The only catch being that all newlydeveloped source code must be released to the public whether they want it to or not. Those applications are considered normal use of the kernel. The gpl only obliges you if you distribute software made from gpld code, and only needs to be accepted when redistribution occurs. This is different from many other projects, which use the default wording in the license to allow gpl v2 or any later version. Bruce perens warns grsecurity breaches the linux kernels. Wouldnt it be better for the community if you did not divide people with this request.
Does distributing a nonfree driver meant to link with the kernel linux violate the gpl. Linux wasnt the first open source software project, but it was the powerful community developed by contributors worldwide. I wish all gpl licensed programs were so good in these respects. Were the android runtime susceptible to the kernels gpl requirements which it isnt, the apache license that android except 3. Linus torvalds on early linux history, gpl license and money. Getapp is your free directory to compare, shortlist and evaluate business solutions. Greg kroah hartman, linux kernel maintainer and fellow at the linux foundation. Linus torvalds on early linux history, gpl license and.
From the wikipedia article on linux the linux kernel is licensed explicitly only under version 2 of the gpl, without offering the licensee the option to choose any later version, which is a common gpl extension. On a normal linux system between the gpl kernel and a nongpl compatible application, there is always the gnu libc, which is lgpl and thus allows derived works that are nonfree. The contract from the linux kernel developers to both grsecurity and the customer which is inherent in the gpl is breached. The gpl doesnt require linux to be free of cost, although the source code is distributed without charge. Even if torvalds had released linux under some other free software license, a free kernel alone would not have made much difference to the world. Many commercial software developers argue that this user written loadable kernel module is not based on linux or a derivative of linux, but is separate and independent and they should not be compelled to license it under gpl.
On august 8, 2003 the free software foundation fsf is conducting a one day seminar on the gnu general public license gnu gpl at stanford university in stanford california usa. The biggest single concern shared by software developers new to linux is that because linux is subject to the gpl, any software written or compiled under linux is also subject to the gpl. It is a unixlike operating system released under the gnu general public license version gplv2. The linux kernel, cddl and related issues software. This documentation file is not meant to replace the copying file, but provides a description of how each source file should be annotated to make the licensing it. The source for the linux kernel used in windows subsystem for linux 2 wsl2 microsoftwsl2linuxkernel. If software requires a modified linux kernel to function, is it considered a derivative work of the linux kernel. Top 10 best open source softwares that rocks world wide. Does all gnu software use the gnu gpl as its license. The gpl allows you to modify, copy, and distribute software licensed under it, provided you also license the derived work under the gpl, and make available the source code. The answer to both questions is the gpl, or gnu general public license, the software license that governs the linux kernel and other opensource software. As far as i know, gpl license gives you freedom given that you apply the same license to your version of the software. The gnu public license version 2 gplv2 is arguably the most important opensource. Busybox is licensed under the gnu general public license.
Big four linux companies shift opensource licensing. I wish all gpllicensed programs were so good in these respects. Vmware heads to court over gpl violations infoworld. Historically, the gpl license family has been one of the most popular software licenses in the free and opensource software domain. The linux kernel is licensed under the gnu general public license. The linux kernel has no structures in place to facilitate relicensing. Within android, linux the kernel remains a separate program, with its source code under gnu gpl version 2. The linux kernel is released under the gnu general public license version 2. The linux kernel is a prominent example of free and open source software. What stipulates that the source code of any software published under its license must be freely available. Frequently asked questions about the gnu licenses gnu project.
The linux kernel as a whole, as it is clearly stated in the copying file, is released under the gnu general public license version 2 gplv2, but it also contains several files under other compatible licenses and an ad hoc exemption for the userspace api header files uapi. There was a debate over how easily it could be changed to use later gpl versions such as version 3 and whether this is even desirable. The significance of linux came from fitting into a larger framework, a complete free operating system. The gnu public license version 2 gplv2 is arguably the most important open source.
The kernel community has taken measures in many cases to encourage, assist, or require of parties making nongpld modules that they comply with the kernels license terms. Big four linux companies shift opensource licensing policies. Before the gpl, torvalds distributed linux under a different license of his own creation. The gpl the gnu general public license the most popular copyleft licence, sometimes gets a. Writing proprietary and possibly closed source software while. The gnu general public license gpl has governed the linux kernel since 1992. For example, type the following command to find a copy of that file in your linux system for various items. Now, if you have a nonfree libc, that might be considered a derived work, since you are directly calling the kernel, and also using kernel headers. The intricacies of using the gpl license have been hashed out repeatedly in many other forums. Here are some highlights of a few specific issues that come up occasionaly. If linux is gpl, then how is android apachelicensed.
The answer to both questions is the gpl, or gnu general public license, the software license that governs the linux kernel and other. However, gpled code can link against closedsource libraries without altering the license of those libraries otherwise, we could make every library in existence opensource simply by writing a gpl program and linking it against the library. All source code can be freely used, modified and redistributed by anyone under the gpl. This means it is unlikely that the kernel will switch to gpl version 3. How can semiproprietary software be based on the linux. Gpl was the first copyleft license for general use. Cddl is a free software license, originally written and used by sun microsystems to release various programs ed by sun. The gpl assures that the kernel source code will always remain available. This article by jerry epplin sheds some light on the issues associated with using gpl software in embedded applications, and attempts to dispel the.
The linux kernel is licensed under the gnu general public license, version 2. For existing kernel code the or any later version option is. The linux kernel is provided under the terms of the gnu general public license version 2 only gpl2. Being under the terms of the gnu general public license version 2 only, according with. Gnulinux is one of the most important examples of free software, the terms used to refer to the unix free operating system, often using the gnu system tools. There is also a special exemption for the linux kernel headers and libgcc the library implicitly called to by the compiler. This means that developers can modify or add new features to the linux kernel as they please. Browse other questions tagged gpl linuxkernel or ask your own question. After all, the gpl requires each copy of covered software to. The linux kernel, developed by contributors worldwide, is a prominent example of free and open source software.
570 160 1515 1092 1351 1046 54 235 357 294 416 555 172 66 599 1206 699 1420 302 340 1117 314 1193 442 1116 306 1228 1082 1494 715 106 1375 780 1067 869 543