the-gnu-project

windows版本的emacs

   their own distribution terms, or even turned the work into a
   proprietary software package.  I had no intention of doing a large
   amount of work only to see it become useless for its intended purpose:
   creating a new software-sharing community.

   However, Professor Winston, then the head of the MIT AI Lab, kindly
   invited me to keep using the lab's facilities.

  The first steps

   Shortly before beginning the GNU project, I heard about the Free
   University Compiler Kit, also known as VUCK.  (The Dutch word for
   "free" is written with a V.)  This was a compiler designed to handle
   multiple languages, including C and Pascal, and to support multiple
   target machines.  I wrote to its author asking if GNU could use it.

   He responded derisively, stating that the university was free but the
   compiler was not.  I therefore decided that my first program for the
   GNU project would be a multi-language, multi-platform compiler.

   Hoping to avoid the need to write the whole compiler myself, I
   obtained the source code for the Pastel compiler, which was a
   multi-platform compiler developed at Lawrence Livermore Lab.  It
   supported, and was written in, an extended version of Pascal, designed
   to be a system-programming language.  I added a C front end, and began
   porting it to the Motorola 68000 computer.  But I had to give that up
   when I discovered that the compiler needed many megabytes of stack
   space, and the available 68000 Unix system would only allow 64k.

   I then realized that the Pastel compiler functioned by parsing the
   entire input file into a syntax tree, converting the whole syntax tree
   into a chain of "instructions", and then generating the whole output
   file, without ever freeing any storage.  At this point, I concluded I
   would have to write a new compiler from scratch.  That new compiler is
   now known as GCC; none of the Pastel compiler is used in it, but I
   managed to adapt and use the C front end that I had written.  But that
   was some years later; first, I worked on GNU Emacs.

  GNU Emacs

   I began work on GNU Emacs in September 1984, and in early 1985 it was
   beginning to be usable.  This enabled me to begin using Unix systems to
   do editing; having no interest in learning to use vi or ed, I had done
   my editing on other kinds of machines until then.

   At this point, people began wanting to use GNU Emacs, which raised the
   question of how to distribute it.  Of course, I put it on the anonymous
   ftp server on the MIT computer that I used.  (This computer,
   prep.ai.mit.edu, thus became the principal GNU ftp distribution site;
   when it was decommissioned a few years later, we transferred the name
   to our new ftp server.)  But at that time, many of the interested
   people were not on the Internet and could not get a copy by ftp.  So
   the question was, what would I say to them?

   I could have said, "Find a friend who is on the net and who will make
   a copy for you."  Or I could have done what I did with the original
   PDP-10 Emacs: tell them, "Mail me a tape and a SASE, and I will mail
   it back with Emacs on it."  But I had no job, and I was looking for
   ways to make money from free software.  So I announced that I would
   mail a tape to whoever wanted one, for a fee of $150.  In this way, I
   started a free software distribution business, the precursor of the
   companies that today distribute entire Linux-based GNU systems.

  Is a program free for every user?

   If a program is free software when it leaves the hands of its author,
   this does not necessarily mean it will be free software for everyone
   who has a copy of it.  For example, public domain software (software
   that is not copyrighted) is free software; but anyone can make a
   proprietary modified version of it.  Likewise, many free programs are
   copyrighted but distributed under simple permissive licenses which
   allow proprietary modified versions.

   The paradigmatic example of this problem is the X Window System.
   Developed at MIT, and released as free software with a permissive
   license, it was soon adopted by various computer companies.  They added
   X to their proprietary Unix systems, in binary form only, and covered
   by the same nondisclosure agreement.  These copies of X were no more
   free software than Unix was.

   The developers of the X Window System did not consider this a
   problem--they expected and intended this to happen.  Their goal was not
   freedom, just "success", defined as "having many users."  They did not
   care whether these users had freedom, only that they should be
   numerous.

   This lead to a paradoxical situation where two different ways of
   counting the amount of freedom gave different answers to the question,
   "Is this program free?" If you judged based on the freedom provided by
   the distribution terms of the MIT release, you would say that X was
   free software.  But if you measured the freedom of the average user of
   X, you would have to say it was proprietary software.  Most X users
   were running the proprietary versions that came with Unix systems, not
   the free version.

  Copyleft and the GNU GPL

   The goal of GNU was to give users freedom, not just to be popular.  So
   we needed to use distribution terms that would prevent GNU software
   from being turned into proprietary software.  The method we use is
   called "copyleft".(1)

   Copyleft uses copyright law, but flips it over to serve the opposite
   of its usual purpose: instead of a means of privatizing software, it
   becomes a means of keeping software free.

   The central idea of copyleft is that we give everyone permission to
   run the program, copy the program, modify the program, and distribute
   modified versions--but not permission to add restrictions of their
   own.  Thus, the crucial freedoms that define "free software" are
   guaranteed to everyone who has a copy; they become inalienable rights.

   For an effective copyleft, modified versions must also be free.  This
   ensures that work based on ours becomes available to our community if
   it is published.  When programmers who have jobs as programmers
   volunteer to improve GNU software, it is copyleft that prevents their
   employers from saying, "You can't share those changes, because we are
   going to use them to make our proprietary version of the program."

   The requirement that changes must be free is essential if we want to
   ensure freedom for every user of the program.  The companies that
   privatized the X Window System usually made some changes to port it to
   their systems and hardware.  These changes were small compared with the
   great extent of X, but they were not trivial.  If making changes were
   an excuse to deny the users freedom, it would be easy for anyone to
   take advantage of the excuse.

   A related issue concerns combining a free program with non-free code.
   Such a combination would inevitably be non-free; whichever freedoms
   are lacking for the non-free part would be lacking for the whole as
   well.  To permit such combinations would open a hole big enough to sink
   a ship.  Therefore, a crucial requirement for copyleft is to plug this
   hole: anything added to or combined with a copylefted program must be
   such that the larger combined version is also free and copylefted.

   The specific implementation of copyleft that we use for most GNU
   software is the GNU General Public License, or GNU GPL for short.  We
   have other kinds of copyleft that are used in specific circumstances.
   GNU manuals are copylefted also, but use a much simpler kind of
   copyleft, because the complexity of the GNU GPL is not necessary for
   manuals.

   (1) In 1984 or 1985, Don Hopkins (a very imaginative fellow) mailed me
   a letter.  On the envelope he had written several amusing sayings,
   including this one: "Copyleft--all rights reversed." I used the word
   "copyleft" to name the distribution concept I was developing at the
   time.

  The Free Software Foundation

   As interest in using Emacs was growing, other people became involved
   in the GNU project, and we decided that it was time to seek funding
   once again.  So in 1985 we created the Free Software Foundation, a
   tax-exempt charity for free software development.  The FSF also took
   over the Emacs tape distribution business; later it extended this by
   adding other free software (both GNU and non-GNU) to the tape, and by
   selling free manuals as well.

   The FSF accepts donations, but most of its income has always come from
   sales--of copies of free software, and of other related services.
   Today it sells CD-ROMs of source code, CD-ROMs with binaries, nicely
   printed manuals (all with freedom to redistribute and modify), and
   Deluxe Distributions (where we build the whole collection of software
   for your choice of platform).

   Free Software Foundation employees have written and maintained a
   number of GNU software packages.  Two notable ones are the C library
   and the shell.  The GNU C library is what every program running on a
   GNU/Linux system uses to communicate with Linux.  It was developed by a
   member of the Free Software Foundation staff, Roland McGrath.  The
   shell used on most GNU/Linux systems is BASH, the Bourne Again
   Shell(1), which was developed by FSF employee Brian Fox.

   We funded development of these programs because the GNU project was
   not just about tools or a development environment.  Our goal was a
   complete operating system, and these programs were needed for that
   goal.

   (1) "Bourne again Shell" is a joke on the name ``Bourne Shell'', which
   was the usual shell on Unix.

  Free software support

   The free software philosophy rejects a specific widespread business
   practice, but it is not against business.  When businesses respect the
   users' freedom, we wish them success.

   Selling copies of Emacs demonstrates one kind of free software
   business.  When the FSF took over that business, I needed another way
   to make a living.  I found it in selling services relating to the free
   software I had developed.  This included teaching, for subjects such as
   how to program GNU Emacs and how to customize GCC, and software
   development, mostly porting GCC to new platforms.

   Today each of these kinds of free software business is practiced by a
   number of corporations.  Some distribute free software collections on
   CD-ROM; others sell support at levels ranging from answering user
   questions, to fixing bugs, to adding major new features.  We are even
   beginning to see free software companies based on launching new free
   software products.

   Watch out, though--a number of companies that associate themselves
   with the term "open source" actually base their business on non-free
   software that works with free software.  These are not free software
   companies, they are proprietary software companies whose products
   tempt users away from freedom.  They call these "value added", which
   reflects the values they would like us to adopt: convenience above
   freedom.  If we value freedom more, we should call them "freedom
   subtracted" products.

  Technical goals

   The principal goal of GNU was to be free software.  Even if GNU had no
   technical advantage over Unix, it would have a social advantage,
   allowing users to cooperate, and an ethical advantage, respecting the
   user's freedom.

   But it was natural to apply the known standards of good practice to
   the work--for example, dynamically allocating data structures to avoid
   arbitrary fixed size limits, and handling all the possible 8-bit codes
   wherever that made sense.

   In addition, we rejected the Unix focus on small memory size, by
   deciding not to support 16-bit machines (it was clear that 32-bit
   machines would be the norm by the time the GNU system was finished),
   and to make no effort to reduce memory usage unless it exceeded a