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diff --git a/talermerchantdemos/blog/articles/scrap1_21.html b/talermerchantdemos/blog/articles/scrap1_21.html new file mode 100644 index 0000000..f2ed919 --- /dev/null +++ b/talermerchantdemos/blog/articles/scrap1_21.html @@ -0,0 +1,211 @@ +<!-- This is the second edition of Free Software, Free Society: Selected Essays of Richard M. Stallman. + +Free Software Foundation + +51 Franklin Street, Fifth Floor + +Boston, MA 02110-1335 +Copyright C 2002, 2010 Free Software Foundation, Inc. +Verbatim copying and distribution of this entire book are permitted +worldwide, without royalty, in any medium, provided this notice is +preserved. Permission is granted to copy and distribute translations +of this book from the original English into another language provided +the translation has been approved by the Free Software Foundation and +the copyright notice and this permission notice are preserved on all +copies. + +ISBN 978-0-9831592-0-9 +Cover design by Rob Myers. + +Cover photograph by Peter Hinely. + --> + + + <a name="What-Is-Copyleft_003f"> + </a> + <h1 class="chapter"> + 21. What Is Copyleft? + </h1> + <a name="index-GPL-2"> + </a> + <a name="index-copyleft-_0028see-also-copyright_0029-3"> + </a> + <a name="index-copylefted-software-_0028see-also-software_0029-1"> + </a> + <p> + Copyleft is a general method for making a program (or +other work) free, and requiring all modified and extended versions of the +program to be free as well. + </p> + <a name="index-public-domain-software-_0028see-also-software_0029-4"> + </a> + <p> + The simplest way to make a program free software is to put it in the +public domain, uncopyrighted. This allows people to +share the program and their improvements, if they are so minded. But +it also allows uncooperative people to convert the program into +proprietary software. They can make changes, many or few, +and distribute the result as a proprietary product. People who +receive the program in that modified form do not have the freedom that +the original author gave them; the middleman has stripped it away. + </p> + <p> + In the GNU Project, our aim is +to give + <em> + all + </em> + users the freedom to redistribute and change GNU +software. If middlemen could strip off the freedom, we might have +many users, but those users would not have freedom. So instead of +putting GNU software in the public domain, we “copyleft” +it. Copyleft says that anyone who redistributes the software, with or +without changes, must pass along the freedom to further copy and +change it. Copyleft guarantees that every user has freedom. + </p> + <p> + Copyleft also provides an incentive for other programmers to add to +free software. Important free programs such as the + <a name="index-GNU_002c-GNU-C_002b_002b-compiler"> + </a> + GNU C++ compiler +exist only because of this. + </p> + <p> + Copyleft also helps programmers who want to contribute improvements to +free software get permission to +do so. These programmers often work for companies or universities +that would do almost anything to get more money. A programmer may +want to contribute her changes to the community, but her employer may +want to turn the changes into a proprietary software product. + </p> + <p> + When we explain to the employer that it is illegal to distribute the +improved version except as free software, the employer usually decides +to release it as free software rather than throw it away. + </p> + <p> + To copyleft a program, we first state that it is copyrighted; then we +add distribution terms, which are a legal instrument that gives +everyone the rights to use, modify, and redistribute the program’s +code, + <em> + or any program derived from it, + </em> + but only if the +distribution terms are unchanged. Thus, the code and the freedoms +become legally inseparable. + </p> + <p> + Proprietary software developers use copyright to take away the users’ +freedom; we use copyright to guarantee their freedom. That’s why we +reverse the name, changing “copyright” into +“copyleft.” + </p> + <p> + Copyleft is a way of using of the copyright on the program. It +doesn’t mean abandoning the copyright; in fact, doing so would make +copyleft impossible. The “left” in +“copyleft” is not a reference to the verb “to +leave”—only to the direction which is the inverse of +“right.” + </p> + <p> + Copyleft is a general concept, and you can’t use a general concept +directly; you can only use a specific implementation of the concept. +In the GNU Project, the specific distribution terms that we use for +most software are contained in the GNU General Public License. The GNU General Public License is often called the GNU GPL for +short. There is also a Frequently Asked Questions page about the GNU +GPL, at + <a href="http://gnu.org/licenses/gpl-faq.html"> + http://gnu.org/licenses/gpl-faq.html + </a> + . You can also +read about why the FSF gets copyright assignments from contributors, +at + <a href="http://gnu.org/copyleft/why-assign.html"> + http://gnu.org/copyleft/why-assign.html + </a> + . + </p> + <a name="index-libraries-_0028comp_002e_0029_002c-LGPL-and"> + </a> + <a name="index-LGPL_002c-and-GNU-libraries"> + </a> + <a name="index-GNU_002c-GNU-libraries"> + </a> + <a name="index-libraries-_0028comp_002e_0029_002c-GNU-1"> + </a> + <p> + An alternate form of copyleft, the GNU Lesser General Public License +(LGPL), applies to a few (but not all) GNU libraries. To +learn more about properly using the LGPL, please read the article +“Why You Shouldn’t Use the Lesser GPL for Your Next Library,” +available at + <a href="http://gnu.org/philosophy/why-not-lgpl.html"> + http://gnu.org/philosophy/why-not-lgpl.html + </a> + . + </p> + <a name="index-manuals_002c-FDL-and"> + </a> + <a name="index-FDL-_0028see-also-both-manuals-and-documentation_0029-1"> + </a> + <p> + The GNU Free Documentation License (FDL) is a form of +copyleft intended for use on a manual, textbook or other document to +assure everyone the effective freedom to copy and redistribute it, +with or without modifications, either commercially or noncommercially. + </p> + <p> + The appropriate license is included in many manuals and in each GNU +source code distribution. + </p> + <p> + All these licenses are designed so that you can easily apply them to +your own works, assuming you are the copyright holder. You don’t have +to modify the license to do this, just include a copy of the license +in the work, and add notices in the source files that refer properly +to the license. + </p> + <a name="index-LGPL_002c-altering-distribution-terms-to-GPL"> + </a> + <p> + Using the same distribution terms for many different programs makes it +easy to copy code between various different programs. When they all +have the same distribution terms, there is no problem. The Lesser +GPL, version 2, includes a provision that lets you alter the +distribution terms to the ordinary GPL, so that you can copy code into +another program covered by the GPL. Version 3 of the Lesser GPL is +built as an exception added to GPL version 3, making the compatibility +automatic. + </p> + <p> + If you would like to copyleft your program with the GNU GPL or the GNU +LGPL, please see the license instructions page, at + <a href="http://gnu.org/copyleft/gpl-howto.html"> + http://gnu.org/copyleft/gpl-howto.html + </a> + , for advice. +Please note that you must use the entire text of the license you +choose. Each is an integral whole, and partial copies are not +permitted. + </p> + <p> + If you would like to copyleft your manual with the GNU FDL, please see +the instructions at the end of the FDL text, and the GFDL +instructions page, at + <a href="http://gnu.org/copyleft/fdl-howto.html"> + http://gnu.org/copyleft/fdl-howto.html + </a> + . Again, partial +copies are not permitted. + <a name="index-copylefted-software-_0028see-also-software_0029-2"> + </a> + <a name="index-copyleft-_0028see-also-copyright_0029-4"> + </a> + <a name="index-GPL-3"> + </a> + </p> + <hr size="2"/> + |