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2 | pj | 1 | What Is Copyleft? |
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3 | --------------------------------------------------------------------------- |
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4 | |||
5 | Table of Contents |
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6 | |||
7 | * What Is Copyleft? |
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8 | * Translations of the GPL |
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9 | * Other Texts to Read |
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10 | |||
11 | --------------------------------------------------------------------------- |
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13 | What Is Copyleft? |
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14 | |||
15 | The simplest way to make a program free is to put it in the public domain |
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16 | (18k characters), uncopyrighted. This allows people to share the program |
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17 | and their improvements, if they are so minded. But it also allows |
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18 | uncooperative people to convert the program into proprietary software (18k |
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19 | characters). They can make changes, many or few, and distribute the result |
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20 | as a proprietary product. People who receive the program in that modified |
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21 | form do not have the freedom that the original author gave them; the |
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22 | middleman has stripped it away. |
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23 | |||
24 | In the GNU project, our aim is to give all users the freedom to |
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25 | redistribute and change GNU software. If middlemen could strip off the |
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26 | freedom, we might have many users, but those users would not have freedom. |
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27 | So instead of putting GNU software in the public domain, we ``copyleft'' |
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28 | it. Copyleft says that anyone who redistributes the software, with or |
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29 | without changes, must pass along the freedom to further copy and change it. |
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30 | Copyleft guarantees that every user has freedom. |
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31 | |||
32 | Copyleft provides another benefit as well. People who write improvements in |
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33 | free software often work for companies or universities that would do almost |
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34 | anything to get money. A programmer may want to contribute her changes to |
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35 | the community, but her employer may ``see green'' and insist on turning the |
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36 | changes into a commercial product. |
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37 | |||
38 | When we explain to the employer that it is illegal to distribute the |
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39 | improved version except as free software, the employer usually decides to |
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40 | release it as free software rather than throw it away. |
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41 | |||
42 | To copyleft a program, first we copyright it; then we add distribution |
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43 | terms, which are a legal instrument that gives everyone the rights to use, |
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44 | modify, and redistribute the program's code or any program derived from it |
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45 | but only if the distribution terms are unchanged. Thus, the code and the |
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46 | freedoms become legally inseparable. |
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47 | |||
48 | Proprietary software developers use copyright to take away the users' |
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49 | freedom; we use copyright to guarantee their freedom. That's why we reverse |
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50 | the name, changing ``copyright'' into ``copyleft.'' |
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51 | |||
52 | Copyleft is a general concept; there are many ways to fill in the details. |
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53 | In the GNU Project, the specific distribution terms that we use are |
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54 | contained in the GNU General Public License (20k characters) (GNU GPL). An |
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55 | alternate form, the GNU Library General Public License (27k characters) |
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56 | (GNU LGPL), applies to a few (but not all) GNU libraries. The library |
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57 | license permits linking the libraries into proprietary executables under |
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58 | certain conditions. |
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59 | |||
60 | The appropriate license is included in many manuals and in each GNU source |
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61 | code distribution (usually in files named COPYING (20k characters) and |
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62 | COPYING.LIB (27k characters)). |
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63 | |||
64 | The GNU GPL is designed so that you can easily apply it to your own program |
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65 | if you are the copyright holder. You don't have to modify the GNU GPL to do |
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66 | this, just add notices to your program which refer properly to the GNU GPL. |
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67 | |||
68 | If you would like to copyleft your program with the GNU GPL, please see the |
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69 | instructions at the end (20k characters) of the GPL text. If you would like |
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70 | to copyleft your library with the GNU LGPL, please see the instructions at |
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71 | the end (27k characters) of the LGPL text (note you can also use the |
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72 | ordinary GPL for libraries). |
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73 | |||
74 | Using the same distribution terms for many different programs makes it easy |
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75 | to copy code between various different programs. Since they all have the |
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76 | same distribution terms, there is no need to think about whether the terms |
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77 | are compatible. The Library GPL includes a provision that lets you alter |
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78 | the distribution terms to the ordinary GPL, so that you can copy code into |
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79 | another program covered by the GPL. |
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80 | --------------------------------------------------------------------------- |
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81 | |||
82 | Translations of the GPL |
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83 | |||
84 | Here are some translations of the GNU GPL done by others. |
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85 | |||
86 | * A Japanese translation of the GPL. |
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87 | * A German translation of the GPL. |
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88 | |||
89 | These versions are not official. Legally speaking, the original (English) |
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90 | version of the GPL is what specifies the actual distribution terms for GNU |
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91 | programs. |
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92 | |||
93 | The reason the FSF does not approve these translations as officially valid |
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94 | is that checking them would be difficult and expensive (needing the help of |
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95 | bilingual lawyers in other countries). Even worse, if an error did slip |
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96 | through, the results could be disastrous for the whole free software |
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97 | community. As long as the translations are unofficial, they can't do any |
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98 | harm, and we hope they help more people understand the GPL. |
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99 | --------------------------------------------------------------------------- |
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100 | |||
101 | Other Texts to Read |
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102 | |||
103 | This first group of articles directly address the philosophy of the GNU |
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104 | project and free software: |
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105 | |||
106 | * What is Free Software? |
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107 | * Why Software Should Not Have Owners |
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108 | * Selling Free Software Can Be Ok! |
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109 | * Categories of Free Software (18k characters) |
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110 | * Free software is more reliable! |
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111 | * What is the Free Software Foundation? |
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112 | * What is Copyleft? |
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113 | * Confusing Words which You Might Want to Avoid |
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114 | * History of the GNU Project |
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115 | * The GNU Manifesto (31k characters) |
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116 | * Why there are no GIF files on GNU web pages |
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117 | |||
118 | This second group of articles deal with related topics but are not directly |
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119 | about the GNU project: |
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120 | |||
121 | * How to Protect the Right to Write Software (independent of whether |
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122 | it's free or not) |
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123 | * Where the Copyright System and Government Plans are Leading Us |
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124 | * The Right Way to Tax DAT (22k characters) |
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125 | * Studies Find Reward Often No Motivator |
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126 | * A speech that Richard Stallman gave in 1986 at the Royal Institute of |
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127 | Technology in Sweden |
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128 | * How to Protect the Freedoms of Speech, Press, and Association on the |
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129 | Internet |
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130 | |||
131 | --------------------------------------------------------------------------- |
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132 | |||
133 | FSF & GNU inquiries & questions to gnu@prep.ai.mit.edu. Other ways to |
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134 | contact the FSF. |
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135 | |||
136 | Copyright (C) 1996, 1997 Free Software Foundation, Inc., 59 Temple Place - |
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137 | Suite 330, Boston, MA 02111, USA |
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138 | |||
139 | Verbatim copying and distribution is permitted in any medium, provided this |
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140 | notice is preserved. |
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141 | |||
142 | Updated: 4 Aug 1997 tower |
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143 | --------------------------------------------------------------------------- |