+@node References
+@chapter References to Non-Free Software and Documentation
+@cindex references to non-free material
+
+A GNU program should not recommend use of any non-free program. We
+can't stop some people from writing proprietary programs, or stop
+other people from using them, but we can and should refuse to
+advertise them to new potential customers. Proprietary software is a
+social and ethical problem, and the point of GNU is to solve that
+problem.
+
+The GNU definition of free software is found on the GNU web site at
+@url{http://www.gnu.org/philosophy/free-sw.html}, and the definition
+of free documentation is found at
+@url{http://www.gnu.org/philosophy/free-doc.html}. A list of
+important licenses and whether they qualify as free is in
+@url{http://www.gnu.org/@/licenses/@/license-list.html}. The terms
+``free'' and ``non-free'', used in this document, refer to that
+definition. If it is not clear whether a license qualifies as free
+under this definition, please ask the GNU Project by writing to
+@email{licensing@@gnu.org}. We will answer, and if the license is an
+important one, we will add it to the list.
+
+When a non-free program or system is well known, you can mention it in
+passing---that is harmless, since users who might want to use it
+probably already know about it. For instance, it is fine to explain
+how to build your package on top of some widely used non-free
+operating system, or how to use it together with some widely used
+non-free program.
+
+However, you should give only the necessary information to help those
+who already use the non-free program to use your program with
+it---don't give, or refer to, any further information about the
+proprietary program, and don't imply that the proprietary program
+enhances your program, or that its existence is in any way a good
+thing. The goal should be that people already using the proprietary
+program will get the advice they need about how to use your free
+program with it, while people who don't already use the proprietary
+program will not see anything to lead them to take an interest in it.
+
+If a non-free program or system is obscure in your program's domain,
+your program should not mention or support it at all, since doing so
+would tend to popularize the non-free program more than it popularizes
+your program. (You cannot hope to find many additional users among
+the users of Foobar if the users of Foobar are few.)
+
+Sometimes a program is free software in itself but depends on a
+non-free platform in order to run. For instance, many Java programs
+depend on the parts of Sun's Java implementation which are not yet
+free software, and won't run on the GNU Java Compiler (which does not
+yet have all the features) or won't run with the GNU Java libraries.
+We hope this particular problem will be gone in a few months, when Sun
+makes the standard Java libraries free software, but of course the
+general principle remains: you should not recommend programs that
+depend on non-free software to run.
+
+Some free programs encourage the use of non-free software. A typical
+example is @command{mplayer}. It is free software in itself, and the
+free code can handle some kinds of files. However, @command{mplayer}
+recommends use of non-free codecs for other kinds of files, and users
+that install @command{mplayer} are very likely to install those codecs
+along with it. To recommend @command{mplayer} is, in effect, to
+recommend the non-free codecs. We must not do that, so we cannot
+recommend @command{mplayer} either.
+
+In general, you should also not recommend programs that themselves
+strongly recommend the use of non-free software.
+
+A GNU package should not refer the user to any non-free documentation
+for free software. Free documentation that can be included in free
+operating systems is essential for completing the GNU system, or any
+free operating system, so it is a major focus of the GNU Project; to
+recommend use of documentation that we are not allowed to use in GNU
+would weaken the impetus for the community to produce documentation
+that we can include. So GNU packages should never recommend non-free
+documentation.
+
+By contrast, it is ok to refer to journal articles and textbooks in
+the comments of a program for explanation of how it functions, even
+though they be non-free. This is because we don't include such things
+in the GNU system even if we are allowed to---they are outside the
+scope of an operating system project.
+
+Referring to a web site that describes or recommends a non-free
+program is in effect promoting that software, so please do not make
+links (or mention by name) web sites that contain such material. This
+policy is relevant particularly for the web pages for a GNU package.
+
+Following links from nearly any web site can lead to non-free
+software; this is an inescapable aspect of the nature of the web, and
+in itself is no objection to linking to a site. As long as the site
+does not itself recommend a non-free program, there is no need be
+concerned about the sites it links to for other reasons.
+
+Thus, for example, you should not make a link to AT&T's web site,
+because that recommends AT&T's non-free software packages; you should
+not make a link to a site that links to AT&T's site saying it is a
+place to get a non-free program; but if a site you want to link to
+refers to AT&T's web site in some other context (such as long-distance
+telephone service), that is not a problem.
+
+
+@node GNU Free Documentation License
+@appendix GNU Free Documentation License
+
+@cindex FDL, GNU Free Documentation License
+@include fdl.texi
+
+@node Index
+@unnumbered Index
+@printindex cp