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Info file emacs, produced by texinfo-format-buffer -*-Text-*- from file emacs.tex This file documents the GNU Emacs editor. Copyright (C) 1985, 1986 Richard M. Stallman. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the sections entitled "The GNU Manifesto", "Distribution" and "GNU Emacs General Public License" are included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the sections entitled "The GNU Manifesto", "Distribution" and "GNU Emacs General Public License" may be included in a translation approved by the author instead of in the original English. File: emacs Node: Syntax Change, Prev: Syntax Entry, Up: Syntax Altering Syntax Information --------------------------- It is possible to alter a character's syntax table entry by storing a new number in the appropriate element of the syntax table, but it would be hard to determine what number to use. Therefore, Emacs provides a command that allows you to specify the syntactic properties of a character in a convenient way. `M-x modify-syntax-entry' is the command to change a character's syntax. It can be used interactively, and is also the means used by major modes to initialize their own syntax tables. Its first argument is the character to change. The second argument is a string that specifies the new syntax. When called from Lisp code, there is a third, optional argument, which specifies the syntax table in which to make the change. If not supplied, or if this command is called interactively, the third argument defaults to the current buffer's syntax table. 1. The first character in the string specifies the syntactic class. It is one of the characters in the previous table (*Note Syntax Entry::). 2. The second character is the matching delimiter. For a character that is not an opening or closing delimiter, this should be a space, and may be omitted if no following characters are needed. 3. The remaining characters are flags. The flag characters allowed are `1' Flag this character as the first of a two-character comment starting sequence. `2' Flag this character as the second of a two-character comment starting sequence. `3' Flag this character as the first of a two-character comment ending sequence. `4' Flag this character as the second of a two-character comment ending sequence. A description of the contents of the current syntax table can be displayed with `C-h s' (`describe-syntax'). The description of each character includes both the string you would have to give to `modify-syntax-entry' to set up that character's current syntax, and some English to explain that string if necessary. File: emacs Node: Init File, Prev: Syntax, Up: Customization The Init File, .emacs ===================== When Emacs is started, it normally loads the file `.emacs' in your home directory. This file, if it exists, should contain Lisp code. It is called your "init file". The command line switches `-q' and `-u' can be used to tell Emacs whether to load an init file (*Note Entering Emacs::). There can also be a "default init file", which is the library named `default.el', found via the standard search path for libraries. The Emacs distribution contains no such library; your site may create one for local customizations. If this library exists, it is loaded whenever you start Emacs. But your init file, if any, is loaded first; if it sets `inhibit-default-init' non-`nil', then `default' is not loaded. If you have a large amount of code in your `.emacs' file, you should move it into another file named `SOMETHING.el', byte-compile it (*Note Lisp Libraries::), and make your `.emacs' file load the other file using `load'. * Menu: * Init Syntax:: Syntax of constants in Emacs Lisp. * Init Examples:: How to do some things with an init file. * Terminal Init:: Each terminal type can have an init file. File: emacs Node: Init Syntax, Prev: Init File, Up: Init File, Next: Init Examples Init File Syntax ---------------- The `.emacs' file contains one or more Lisp function call expressions. Each of these consists of a function name followed by arguments, all surrounded by parentheses. For example, `(setq fill-column 60)' represents a call to the function `setq' which is used to set the variable `fill-column' (*Note Filling::) to 60. The second argument to `setq' is an expression for the new value of the variable. This can be a constant, a variable, or a function call expression. In `.emacs', constants are used most of the time. They can be: Numbers: Numbers are written in decimal, with an optional initial minus sign. Strings: Lisp string syntax is the same as C string syntax with a few extra features. Use a double-quote character to begin and end a string constant. Newlines and special characters may be present literally in strings. They can also be represented as backslash sequences: `\n' for newline, `\b' for backspace, `\r' for carriage return, `\t' for tab, `\f' for formfeed (control-l), `\e' for escape, `\\' for a backslash, `\"' for a double-quote, or `\OOO' for the character whose octal code is OOO. Backslash and double-quote are the only characters for which backslash sequences are mandatory. `\C-' can be used as a prefix for a control character, as in `\C-s' for ASCII Control-S, and `\M-' can be used as a prefix for a meta character, as in `\M-a' for Meta-A or `\M-\C-a' for Control-Meta-A. Characters: Lisp character constant syntax consists of a `?' followed by either a character or an escape sequence starting with `\'. Examples: `?x', `?\n', `?\"', `?\)'. Note that strings and characters are not interchangeable in Lisp; some contexts require one and some contexts require the other. True: `t' stands for `true'. False: `nil' stands for `false'. Other Lisp objects: Write a single-quote (') followed by the Lisp object you want. File: emacs Node: Init Examples, Prev: Init Syntax, Up: Init File, Next: Terminal Init Init File Examples ------------------ Here are some examples of doing certain commonly desired things with Lisp expressions: * Make TAB in C mode just insert a tab if point is in the middle of a line. (setq c-tab-always-indent nil) Here we have a variable whose value is normally `t' for `true' and the alternative is `nil' for `false'. * Make searches case sensitive by default (in all buffers that do not override this). (setq-default case-fold-search nil) This sets the default value, which is effective in all buffers that do not have local values for the variable. Setting `case-fold-search' with `setq' affects only the current buffer's local value, which is not what you probably want to do in an init file. * Make Text mode the default mode for new buffers. (setq default-major-mode 'text-mode) Note that `text-mode' is used because it is the command for entering the mode we want. A single-quote is written before it to make a symbol constant; otherwise, `text-mode' would be treated as a variable name. * Turn on Auto Fill mode automatically in Text mode and related modes. (setq text-mode-hook '(lambda () (auto-fill-mode 1))) Here we have a variable whose value should be a Lisp function. The function we supply is a list starting with `lambda', and a single quote is written in front of it to make it (for the purpose of this `setq') a list constant rather than an expression. Lisp functions are not explained here, but for mode hooks it is enough to know that `(auto-fill-mode 1)' is an expression that will be executed when Text mode is entered, and you could replace it with any other expression that you like, or with several expressions in a row. (setq text-mode-hook 'turn-on-auto-fill) This is another way to accomplish the same result. `turn-on-auto-fill' is a symbol whose function definition is `(lambda () (auto-fill-mode 1))'. * Load the installed Lisp library named `foo' (actually a file `foo.elc' or `foo.el' in a standard Emacs directory). (load "foo") When the argument to `load' is a relative pathname, not starting with `/' or `~', `load' searches the directories in `load-path' (*Note Loading::). * Load the compiled Lisp file `foo.elc' from your home directory. (load "~/foo.elc") Here an absolute file name is used, so no searching is done. * Rebind the key `C-x l' to run the function `make-symbolic-link'. (global-set-key "\C-xl" 'make-symbolic-link) or (define-key global-map "\C-xl" 'make-symbolic-link) Note once again the single-quote used to refer to the symbol `make-symbolic-link' instead of its value as a variable. * Do the same thing for C mode only. (define-key c-mode-map "\C-xl" 'make-symbolic-link) * Redefine all keys which now run `next-line' in Fundamental mode so that they run `forward-line' instead. (substitute-key-definition 'next-line 'forward-line global-map) * Make `C-x C-v' undefined. (global-unset-key "\C-x\C-v") One reason to undefine a key is so that you can make it a prefix. Simply defining `C-x C-v ANYTHING' would make `C-x C-v' a prefix, but `C-x C-v' must be freed of any non-prefix definition first. * Make `$' have the syntax of punctuation in Text mode. Note the use of a character constant for `$'. (modify-syntax-entry ?\$ "." text-mode-syntax-table) * Enable the use of the command `eval-expression' without confirmation. (put 'eval-expression 'disabled nil) File: emacs Node: Terminal Init, Prev: Init Examples, Up: Init File Terminal-specific Initialization -------------------------------- Each terminal type can have a Lisp library to be loaded into Emacs when it is run on that type of terminal. For a terminal type named TERMTYPE, the library is called `term/TERMTYPE' and it is found by searching the directories `load-path' as usual and trying the suffixes `.elc' and `.el'. Normally it appears in the subdirectory `term' of the directory where most Emacs libraries are kept. The usual purpose of the terminal-specific library is to define the escape sequences used by the terminal's function keys using the library `keypad.el'. See the file `term/vt100.el' for an example of how this is done. When the terminal type contains a hyphen, only the part of the name before the first hyphen is significant in choosing the library name. Thus, terminal types `aaa-48' and `aaa-30-rv' both use the library `term/aaa'. The code in the library can use `(getenv "TERM")' to find the full terminal type name. The library's name is constructed by concatenating the value of the variable `term-file-prefix' and the terminal type. Your `.emacs' file can prevent the loading of the terminal-specific library by setting `term-file-prefix' to `nil'. The value of the variable `term-setup-hook', if not `nil', is called as a function of no arguments at the end of Emacs initialization, after both your `.emacs' file and any terminal-specific library have been read in. You can set the value in the `.emacs' file to override part of any of the terminal-specific libraries and to define initializations for terminals that do not have a library. File: emacs Node: Quitting, Prev: Customization, Up: Top, Next: Lossage Quitting and Aborting ===================== `C-g' Quit. Cancel running or partially typed command. `C-]' Abort innermost recursive editing level and cancel the command which invoked it (`abort-recursive-edit'). `M-x top-level' Abort all recursive editing levels that are currently executing. `C-x u' Cancel an already-executed command, usually (`undo'). There are two ways of cancelling commands which are not finished executing: "quitting" with `C-g', and "aborting" with `C-]' or `M-x top-level'. Quitting is cancelling a partially typed command or one which is already running. Aborting is getting out of a recursive editing level and cancelling the command that invoked the recursive edit. Quitting with `C-g' is used for getting rid of a partially typed command, or a numeric argument that you don't want. It also stops a running command in the middle in a relatively safe way, so you can use it if you accidentally give a command which takes a long time. In particular, it is safe to quit out of killing; either your text will ALL still be there, or it will ALL be in the kill ring (or maybe both). Quitting an incremental search does special things documented under searching; in general, it may take two successive `C-g' characters to get out of a search. `C-g' works by setting the variable `quit-flag' to `t' the instant `C-g' is typed; Emacs Lisp checks this variable frequently and quits if it is non-`nil'. `C-g' is only actually executed as a command if it is typed while Emacs is waiting for input. If you quit twice in a row before the first `C-g' is recognized, you activate the "emergency escape" feature and return to the shell. *Note Emergency Escape::. Aborting with `C-]' (`abort-recursive-edit') is used to get out of a recursive editing level and cancel the command which invoked it. Quitting with `C-g' does not do this, and could not do this, because it is used to cancel a partially typed command within the recursive editing level. Both operations are useful. For example, if you are in the Emacs debugger (*Note Lisp Debug::) and have typed `C-u 8' to enter a numeric argument, you can cancel that argument with `C-g' and remain in the debugger. The command `M-x top-level' is equivalent to "enough" `C-]' commands to get you out of all the levels of recursive edits that you are in. `C-]' gets you out one level at a time, but `M-x top-level' goes out all levels at once. Both `C-]' and `M-x top-level' are like all other commands, and unlike `C-g', in that they are effective only when Emacs is ready for a command. `C-]' is an ordinary key and has its meaning only because of its binding in the keymap. *Note Recursive Edit::. `C-x u' (`undo') is not strictly speaking a way of cancelling a command, but you can think of it as cancelling a command already finished executing. *Note Undo::. File: emacs Node: Lossage, Prev: Quitting, Up: Top, Next: Bugs Dealing with Emacs Trouble ========================== This section describes various conditions in which Emacs fails to work, and how to recognize them and correct them. * Menu: * Stuck Recursive:: `[...]' in mode line around the parentheses * Screen Garbled:: Garbage on the screen * Text Garbled:: Garbage in the text * Unasked-for Search:: Spontaneous entry to incremental search * Emergency Escape:: Emergency escape--- What to do if Emacs stops responding * Total Frustration:: When you are at your wits' end. File: emacs Node: Stuck Recursive, Prev: Lossage, Up: Lossage, Next: Screen Garbled Recursive Editing Levels ------------------------ Recursive editing levels are important and useful features of Emacs, but they can seem like malfunctions to the user who does not understand them. If the mode line has square brackets `[...]' around the parentheses that contain the names of the major and minor modes, you have entered a recursive editing level. If you did not do this on purpose, or if you don't understand what that means, you should just get out of the recursive editing level. To do so, type `M-x top-level'. This is called getting back to top level. *Note Recursive Edit::. File: emacs Node: Screen Garbled, Prev: Stuck Recursive, Up: Lossage, Next: Text Garbled Garbage on the Screen --------------------- If the data on the screen looks wrong, the first thing to do is see whether the text is really wrong. Type `C-l', to redisplay the entire screen. If it appears correct after this, the problem was entirely in the previous screen update. Display updating problems often result from an incorrect termcap entry for the terminal you are using. The file `etc/TERMS' in the Emacs distribution gives the fixes for known problems of this sort. `INSTALL' contains general advice for these problems in one of its sections. Very likely there is simply insufficient padding for certain display operations. To investigate the possibility that you have this sort of problem, try Emacs on another terminal made by a different manufacturer. If problems happen frequently on one kind of terminal but not another kind, it is likely to be a bad termcap entry, though it could also be due to a bug in Emacs that appears for terminals that have or that lack specific features. File: emacs Node: Text Garbled, Prev: Screen Garbled, Up: Lossage, Next: Unasked-for Search Garbage in the Text ------------------- If `C-l' shows that the text is wrong, try undoing the changes to it using `C-x u' until it gets back to a state you consider correct. Also try `C-h l' to find out what command you typed to produce the observed results. If a large portion of text appears to be missing at the beginning or end of the buffer, check for the word `Narrow' in the mode line. If it appears, the text is still present, but marked off-limits. To make it visible again, type `C-x w'. *Note Narrowing::. File: emacs Node: Unasked-for Search, Prev: Text Garbled, Up: Lossage, Next: Emergency Escape Spontaneous Entry to Incremental Search --------------------------------------- If Emacs spontaneously displays `I-search:' at the bottom of the screen, it means that the terminal is sending `C-s' and `C-q' according to the poorly designed xon/xoff "flow control" protocol. You should try to prevent this by putting the terminal in a mode where it will not use flow control or giving it enough padding that it will never send a `C-s'. If that cannot be done, you must tell Emacs to expect flow control to be used, until you can get a properly designed terminal. Information on how to do these things can be found in the file `INSTALL' in the Emacs distribution. File: emacs Node: Emergency Escape, Prev: Unasked-for Search, Up: Lossage, Next: Total Frustration Emergency Escape ---------------- Because at times there have been bugs causing Emacs to loop without checking `quit-flag', a special feature causes Emacs to be suspended immediately if you type a second `C-g' while the flag is already set, so you can always get out of GNU Emacs. Normally Emacs recognizes and clears `quit-flag' (and quits!) quickly enough to prevent this from happening. When you resume Emacs after a suspension caused by multiple `C-g', it asks two questions before going back to what it had been doing: Auto-save? (y or n) Abort (and dump core)? (y or n) Answer each one with `y' or `n' followed by RET. Saying `y' to `Auto-save?' causes immediate auto-saving of all modified buffers in which auto-saving is enabled. Saying `y' to `Abort (and dump core)?' causes an illegal instruction to be executed, dumping core. This is to enable a wizard to figure out why Emacs was failing to quit in the first place. Execution does not continue after a core dump. If you answer `n', execution does continue. With luck, GNU Emacs will ultimately check `quit-flag' and quit normally. If not, and you type another `C-g', it is suspended again. If Emacs is not really hung, just slow, you may invoke the double `C-g' feature without really meaning to. Then just resume and answer `n' to both questions, and you will arrive at your former state. Presumably the quit you requested will happen soon. The double-`C-g' feature may be turned off when Emacs is running under a window system, since the window system always enables you to kill Emacs or to create another window and run another program. File: emacs Node: Total Frustration, Prev: Emergency Escape, Up: Lossage Help for Total Frustration -------------------------- If using Emacs (or something else) becomes terribly frustrating and none of the techniques described above solve the problem, Emacs can still help you. First, if the Emacs you are using is not responding to commands, type `C-g C-g' to get out of it and then start a new one. Second, type `M-x doctor RET'. The doctor will make you feel better. Each time you say something to the doctor, you must end it by typing RET RET. This lets the doctor know you are finished. File: emacs Node: Bugs, Prev: Lossage, Up: Top, Next: Manifesto Reporting Bugs ============== Sometimes you will encounter a bug in Emacs. Although we cannot promise we can or will fix the bug, and we might not even agree that it is a bug, we want to hear about bugs you encounter in case we do want to fix them. To make it possible for us to fix a bug, you must report it. In order to do so effectively, you must know when and how to do it. When Is There a Bug ------------------- If Emacs executes an illegal instruction, or dies with an operating system error message that indicates a problem in the program (as opposed to something like "disk full"), then it is certainly a bug. If Emacs updates the display in a way that does not correspond to what is in the buffer, then it is certainly a bug. If a command seems to do the wrong thing but the problem corrects itself if you type `C-l', it is a case of incorrect display updating. Taking forever to complete a command can be a bug, but you must make certain that it was really Emacs's fault. Some commands simply take a long time. Type `C-g' and then `C-h l' to see whether the input Emacs received was what you intended to type; if the input was such that you KNOW it should have been processed quickly, report a bug. If you don't know whether the command should take a long time, find out by looking in the manual or by asking for assistance. If a command you are familiar with causes an Emacs error message in a case where its usual definition ought to be reasonable, it is probably a bug. If a command does the wrong thing, that is a bug. But be sure you know for certain what it ought to have done. If you aren't familiar with the command, or don't know for certain how the command is supposed to work, then it might actually be working right. Rather than jumping to conclusions, show the problem to someone who knows for certain. Finally, a command's intended definition may not be best for editing with. This is a very important sort of problem, but it is also a matter of judgment. Also, it is easy to come to such a conclusion out of ignorance of some of the existing features. It is probably best not to complain about such a problem until you have checked the documentation in the usual ways, feel confident that you understand it, and know for certain that what you want is not available. If you are not sure what the command is supposed to do after a careful reading of the manual, check the index and glossary for any terms that may be unclear. If you still do not understand, this indicates a bug in the manual. The manual's job is to make everything clear. It is just as important to report documentation bugs as program bugs. If the on-line documentation string of a function or variable disagrees with the manual, one of them must be wrong, so report the bug. How to Report a Bug ------------------- When you decide that there is a bug, it is important to report it and to report it in a way which is useful. What is most useful is an exact description of what commands you type, starting with the shell command to run Emacs, until the problem happens. Always include the version number of Emacs that you are using; type `M-x emacs-version' to print this. The most important principle in reporting a bug is to report FACTS, not hypotheses or categorizations. It is always easier to report the facts, but people seem to prefer to strain to posit explanations and report them instead. If the explanations are based on guesses about how Emacs is implemented, they will be useless; we will have to try to figure out what the facts must have been to lead to such speculations. Sometimes this is impossible. But in any case, it is unnecessary work for us. For example, suppose that you type `C-x C-f /glorp/baz.ugh RET', visiting a file which (you know) happens to be rather large, and Emacs prints out `I feel pretty today'. The best way to report the bug is with a sentence like the preceding one, because it gives all the facts and nothing but the facts. Do not assume that the problem is due to the size of the file and say, "When I visit a large file, Emacs prints out `I feel pretty today'." This is what we mean by "guessing explanations". The problem is just as likely to be due to the fact that there is a `z' in the file name. If this is so, then when we got your report, we would try out the problem with some "large file", probably with no `z' in its name, and not find anything wrong. There is no way in the world that we could guess that we should try visiting a file with a `z' in its name. Alternatively, the problem might be due to the fact that the file starts with exactly 25 spaces. For this reason, you should make sure that you inform us of the exact contents of any file that is needed to reproduce the bug. What if the problem only occurs when you have typed the `C-x C-a' command previously? This is why we ask you to give the exact sequence of characters you typed since starting to use Emacs. You should not even say "visit a file" instead of `C-x C-f' unless you know that it makes no difference which visiting command is used. Similarly, rather than saying "if I have three characters on the line," say "after I type `RET A B C RET C-p'," if that is the way you entered the text. If you are not in Fundamental mode when the problem occurs, you should say what mode you are in. If the manifestation of the bug is an Emacs error message, it is important to report not just the text of the error message but a backtrace showing how the Lisp program in Emacs arrived at the error. To make the backtrace, you must execute the Lisp expression `(setq debug-on-error t)' before the error happens (that is to say, you must execute that expression and then make the bug happen). This causes the Lisp debugger to run (*Note Lisp Debug::). The debugger's backtrace can be copied as text into the bug report. This use of the debugger is possible only if you know how to make the bug happen again. Do note the error message the first time the bug happens, so if you can't make it happen again, you can report at least that. Check whether any programs you have loaded into the Lisp world, including your `.emacs' file, set any variables that may affect the functioning of Emacs. Also, see whether the problem happens in a freshly started Emacs without loading your `.emacs' file (start Emacs with the `-q' switch to prevent loading the init file.) If the problem does NOT occur then, it is essential that we know the contents of any programs that you must load into the Lisp world in order to cause the problem to occur. If the problem does depend on an init file or other Lisp programs that are not part of the standard Emacs system, then you should make sure it is not a bug in those programs by complaining to their maintainers first. After they verify that they are using Emacs in a way that is supposed to work, they should report the bug. If you can tell us a way to cause the problem without visiting any files, please do so. This makes it much easier to debug. If you do need files, make sure you arrange for us to see their exact contents. For example, it can often matter whether there are spaces at the ends of lines, or a newline after the last line in the buffer (nothing ought to care whether the last line is terminated, but tell that to the bugs). The easy way to record the input to Emacs precisely is to to write a dribble file; execute the Lisp expression (open-dribble-file "~/dribble") using `Meta-ESC' or from the `*scratch*' buffer just after starting Emacs. From then on, all Emacs input will be written in the specified dribble file until the Emacs process is killed. For possible display bugs, it is important to report the terminal type (the value of environment variable `TERM'), the complete termcap entry for the terminal from `/etc/termcap' (since that file is not identical on all machines), and the output that Emacs actually sent to the terminal. The way to collect this output is to execute the Lisp expression (open-termscript "~/termscript") using `Meta-ESC' or from the `*scratch*' buffer just after starting Emacs. From then on, all output from Emacs to the terminal will be written in the specified termscript file as well, until the Emacs process is killed. If the problem happens when Emacs starts up, put this expression into your `.emacs' file so that the termscript file will be open when Emacs displays the screen for the first time. Be warned: it is often difficult, and sometimes impossible, to fix a terminal-dependent bug without access to a terminal of the type that stimulates the bug. The address for reporting bugs is GNU Emacs Bugs 545 Tech Sq, rm 703 Cambridge, MA 02139 or send email to `mit-eddie!bug-gnu-emacs' (Usenet) or `bug-gnu-emacs@prep.ai.mit.edu' (Internet). Once again, we do not promise to fix the bug; but if the bug is serious, or ugly, or easy to fix, chances are we will want to. File: emacs Node: Manifesto, Prev: Bugs, Up: Top The GNU Manifesto ***************** What's GNU? Gnu's Not Unix! ============================ GNU, which stands for Gnu's Not Unix, is the name for the complete Unix-compatible software system which I am writing so that I can give it away free to everyone who can use it. Several other volunteers are helping me. Contributions of time, money, programs and equipment are greatly needed. So far we have an Emacs text editor with Lisp for writing editor commands, a source level debugger, a yacc-compatible parser generator, a linker, and around 35 utilities. A shell (command interpreter) is nearly completed. A new portable optimizing C compiler has compiled itself and may be released this year. An initial kernel exists but many more features are needed to emulate Unix. When the kernel and compiler are finished, it will be possible to distribute a GNU system suitable for program development. We will use TeX as our text formatter, but an nroff is being worked on. We will use the free, portable X window system as well. After this we will add a portable Common Lisp, an Empire game, a spreadsheet, and hundreds of other things, plus on-line documentation. We hope to supply, eventually, everything useful that normally comes with a Unix system, and more. GNU will be able to run Unix programs, but will not be identical to Unix. We will make all improvements that are convenient, based on our experience with other operating systems. In particular, we plan to have longer filenames, file version numbers, a crashproof file system, filename completion perhaps, terminal-independent display support, and perhaps eventually a Lisp-based window system through which several Lisp programs and ordinary Unix programs can share a screen. Both C and Lisp will be available as system programming languages. We will try to support UUCP, MIT Chaosnet, and Internet protocols for communication. GNU is aimed initially at machines in the 68000/16000 class with virtual memory, because they are the easiest machines to make it run on. The extra effort to make it run on smaller machines will be left to someone who wants to use it on them. To avoid horrible confusion, please pronounce the `G' in the word `GNU' when it is the name of this project. Why I Must Write GNU ==================== I consider that the golden rule requires that if I like a program I must share it with other people who like it. Software sellers want to divide the users and conquer them, making each user agree not to share with others. I refuse to break solidarity with other users in this way. I cannot in good conscience sign a nondisclosure agreement or a software license agreement. For years I worked within the Artificial Intelligence Lab to resist such tendencies and other inhospitalities, but eventually they had gone too far: I could not remain in an institution where such things are done for me against my will. So that I can continue to use computers without dishonor, I have decided to put together a sufficient body of free software so that I will be able to get along without any software that is not free. I have resigned from the AI lab to deny MIT any legal excuse to prevent me from giving GNU away. Why GNU Will Be Compatible with Unix ==================================== Unix is not my ideal system, but it is not too bad. The essential features of Unix seem to be good ones, and I think I can fill in what Unix lacks without spoiling them. And a system compatible with Unix would be convenient for many other people to adopt. How GNU Will Be Available ========================= GNU is not in the public domain. Everyone will be permitted to modify and redistribute GNU, but no distributor will be allowed to restrict its further redistribution. That is to say, proprietary modifications will not be allowed. I want to make sure that all versions of GNU remain free. Why Many Other Programmers Want to Help ======================================= I have found many other programmers who are excited about GNU and want to help. Many programmers are unhappy about the commercialization of system software. It may enable them to make more money, but it requires them to feel in conflict with other programmers in general rather than feel as comrades. The fundamental act of friendship among programmers is the sharing of programs; marketing arrangements now typically used essentially forbid programmers to treat others as friends. The purchaser of software must choose between friendship and obeying the law. Naturally, many decide that friendship is more important. But those who believe in law often do not feel at ease with either choice. They become cynical and think that programming is just a way of making money. By working on and using GNU rather than proprietary programs, we can be hospitable to everyone and obey the law. In addition, GNU serves as an example to inspire and a banner to rally others to join us in sharing. This can give us a feeling of harmony which is impossible if we use software that is not free. For about half the programmers I talk to, this is an important happiness that money cannot replace. How You Can Contribute ====================== I am asking computer manufacturers for donations of machines and money. I'm asking individuals for donations of programs and work. One consequence you can expect if you donate machines is that GNU will run on them at an early date. The machines should be complete, ready to use systems, approved for use in a residential area, and not in need of sophisticated cooling or power. I have found very many programmers eager to contribute part-time work for GNU. For most projects, such part-time distributed work would be very hard to coordinate; the independently-written parts would not work together. But for the particular task of replacing Unix, this problem is absent. A complete Unix system contains hundreds of utility programs, each of which is documented separately. Most interface specifications are fixed by Unix compatibility. If each contributor can write a compatible replacement for a single Unix utility, and make it work properly in place of the original on a Unix system, then these utilities will work right when put together. Even allowing for Murphy to create a few unexpected problems, assembling these components will be a feasible task. (The kernel will require closer communication and will be worked on by a small, tight group.) If I get donations of money, I may be able to hire a few people full or part time. The salary won't be high by programmers' standards, but I'm looking for people for whom building community spirit is as important as making money. I view this as a way of enabling dedicated people to devote their full energies to working on GNU by sparing them the need to make a living in another way. Why All Computer Users Will Benefit =================================== Once GNU is written, everyone will be able to obtain good system software free, just like air. This means much more than just saving everyone the price of a Unix license. It means that much wasteful duplication of system programming effort will be avoided. This effort can go instead into advancing the state of the art. Complete system sources will be available to everyone. As a result, a user who needs changes in the system will always be free to make them himself, or hire any available programmer or company to make them for him. Users will no longer be at the mercy of one programmer or company which owns the sources and is in sole position to make changes. Schools will be able to provide a much more educational environment by encouraging all students to study and improve the system code. Harvard's computer lab used to have the policy that no program could be installed on the system if its sources were not on public display, and upheld it by actually refusing to install certain programs. I was very much inspired by this. Finally, the overhead of considering who owns the system software and what one is or is not entitled to do with it will be lifted. Arrangements to make people pay for using a program, including licensing of copies, always incur a tremendous cost to society through the cumbersome mechanisms necessary to figure out how much (that is, which programs) a person must pay for. And only a police state can force everyone to obey them. Consider a space station where air must be manufactured at great cost: charging each breather per liter of air may be fair, but wearing the metered gas mask all day and all night is intolerable even if everyone can afford to pay the air bill. And the TV cameras everywhere to see if you ever take the mask off are outrageous. It's better to support the air plant with a head tax and chuck the masks. Copying all or parts of a program is as natural to a programmer as breathing, and as productive. It ought to be as free. Some Easily Rebutted Objections to GNU's Goals ============================================== "Nobody will use it if it is free, because that means they can't rely on any support." "You have to charge for the program to pay for providing the support." If people would rather pay for GNU plus service than get GNU free without service, a company to provide just service to people who have obtained GNU free ought to be profitable. We must distinguish between support in the form of real programming work and mere handholding. The former is something one cannot rely on from a software vendor. If your problem is not shared by enough people, the vendor will tell you to get lost. If your business needs to be able to rely on support, the only way is to have all the necessary sources and tools. Then you can hire any available person to fix your problem; you are not at the mercy of any individual. With Unix, the price of sources puts this out of consideration for most businesses. With GNU this will be easy. It is still possible for there to be no available competent person, but this problem cannot be blamed on distibution arrangements. GNU does not eliminate all the world's problems, only some of them. Meanwhile, the users who know nothing about computers need handholding: doing things for them which they could easily do themselves but don't know how. Such services could be provided by companies that sell just hand-holding and repair service. If it is true that users would rather spend money and get a product with service, they will also be willing to buy the service having got the product free. The service companies will compete in quality and price; users will not be tied to any particular one. Meanwhile, those of us who don't need the service should be able to use the program without paying for the service. "You cannot reach many people without advertising, and you must charge for the program to support that." "It's no use advertising a program people can get free." There are various forms of free or very cheap publicity that can be used to inform numbers of computer users about something like GNU. But it may be true that one can reach more microcomputer users with advertising. If this is really so, a business which advertises the service of copying and mailing GNU for a fee ought to be successful enough to pay for its advertising and more. This way, only the users who benefit from the advertising pay for it. On the other hand, if many people get GNU from their friends, and such companies don't succeed, this will show that advertising was not really necessary to spread GNU. Why is it that free market advocates don't want to let the free market decide this? "My company needs a proprietary operating system to get a competitive edge." GNU will remove operating system software from the realm of competition. You will not be able to get an edge in this area, but neither will your competitors be able to get an edge over you. You and they will compete in other areas, while benefitting mutually in this one. If your business is selling an operating system, you will not like GNU, but that's tough on you. If your business is something else, GNU can save you from being pushed into the expensive business of selling operating systems. I would like to see GNU development supported by gifts from many manufacturers and users, reducing the cost to each. "Don't programmers deserve a reward for their creativity?" If anything deserves a reward, it is social contribution. Creativity can be a social contribution, but only in so far as society is free to use the results. If programmers deserve to be rewarded for creating innovative programs, by the same token they deserve to be punished if they restrict the use of these programs. "Shouldn't a programmer be able to ask for a reward for his creativity?" There is nothing wrong with wanting pay for work, or seeking to maximize one's income, as long as one does not use means that are destructive. But the means customary in the field of software today are based on destruction. Extracting money from users of a program by restricting their use of it is destructive because the restrictions reduce the amount and the ways that the program can be used. This reduces the amount of wealth that humanity derives from the program. When there is a deliberate choice to restrict, the harmful consequences are deliberate destruction. The reason a good citizen does not use such destructive means to become wealthier is that, if everyone did so, we would all become poorer from the mutual destructiveness. This is Kantian ethics; or, the Golden Rule. Since I do not like the consequences that result if everyone hoards information, I am required to consider it wrong for one to do so. Specifically, the desire to be rewarded for one's creativity does not justify depriving the world in general of all or part of that creativity. "Won't programmers starve?" I could answer that nobody is forced to be a programmer. Most of us cannot manage to get any money for standing on the street and making faces. But we are not, as a result, condemned to spend our lives standing on the street making faces, and starving. We do something else. But that is the wrong answer because it accepts the questioner's implicit assumption: that without ownership of software, programmers cannot possibly be paid a cent. Supposedly it is all or nothing. The real reason programmers will not starve is that it will still be possible for them to get paid for programming; just not paid as much as now. Restricting copying is not the only basis for business in software. It is the most common basis because it brings in the most money. If it were prohibited, or rejected by the customer, software business would move to other bases of organization which are now used less often. There are always numerous ways to organize any kind of business. Probably programming will not be as lucrative on the new basis as it is now. But that is not an argument against the change. It is not considered an injustice that sales clerks make the salaries that they now do. If programmers made the same, that would not be an injustice either. (In practice they would still make considerably more than that.) "Don't people have a right to control how their creativity is used?" "Control over the use of one's ideas" really constitutes control over other people's lives; and it is usually used to make their lives more difficult. People who have studied the issue of intellectual property rights carefully (such as lawyers) say that there is no intrinsic right to intellectual property. The kinds of supposed intellectual property rights that the government recognizes were created by specific acts of legislation for specific purposes. For example, the patent system was established to encourage inventors to disclose the details of their inventions. Its purpose was to help society rather than to help inventors. At the time, the life span of 17 years for a patent was short compared with the rate of advance of the state of the art. Since patents are an issue only among manufacturers, for whom the cost and effort of a license agreement are small compared with setting up production, the patents often do not do much harm. They do not obstruct most individuals who use patented products. The idea of copyright did not exist in ancient times, when authors frequently copied other authors at length in works of non-fiction. This practice was useful, and is the only way many authors' works have survived even in part. The copyright system was created expressly for the purpose of encouraging authorship. In the domain for which it was invented---books, which could be copied economically only on a printing press---it did little harm, and did not obstruct most of the individuals who read the books. All intellectual property rights are just licenses granted by society because it was thought, rightly or wrongly, that society as a whole would benefit by granting them. But in any particular situation, we have to ask: are we really better off granting such license? What kind of act are we licensing a person to do? The case of programs today is very different from that of books a hundred years ago. The fact that the easiest way to copy a program is from one neighbor to another, the fact that a program has both source code and object code which are distinct, and the fact that a program is used rather than read and enjoyed, combine to create a situation in which a person who enforces a copyright is harming society as a whole both materially and spiritually; in which a person should not do so regardless of whether the law enables him to. "Competition makes things get done better." The paradigm of competition is a race: by rewarding the winner, we encourage everyone to run faster. When capitalism really works this way, it does a good job; but its defenders are wrong in assuming it always works this way. If the runners forget why the reward is offered and become intent on winning, no matter how, they may find other strategies---such as, attacking other runners. If the runners get into a fist fight, they will all finish late. Proprietary and secret software is the moral equivalent of runners in a fist fight. Sad to say, the only referee we've got does not seem to object to fights; he just regulates them ("For every ten yards you run, you can fire one shot"). He really ought to break them up, and penalize runners for even trying to fight. "Won't everyone stop programming without a monetary incentive?" Actually, many people will program with absolutely no monetary incentive. Programming has an irresistible fascination for some people, usually the people who are best at it. There is no shortage of professional musicians who keep at it even though they have no hope of making a living that way. But really this question, though commonly asked, is not appropriate to the situation. Pay for programmers will not disappear, only become less. So the right question is, will anyone program with a reduced monetary incentive? My experience shows that they will. For more than ten years, many of the world's best programmers worked at the Artificial Intelligence Lab for far less money than they could have had anywhere else. They got many kinds of non-monetary rewards: fame and appreciation, for example. And creativity is also fun, a reward in itself. Then most of them left when offered a chance to do the same interesting work for a lot of money. What the facts show is that people will program for reasons other than riches; but if given a chance to make a lot of money as well, they will come to expect and demand it. Low-paying organizations do poorly in competition with high-paying ones, but they do not have to do badly if the high-paying ones are banned. "We need the programmers desperately. If they demand that we stop helping our neighbors, we have to obey." You're never so desperate that you have to obey this sort of demand. Remember: millions for defense, but not a cent for tribute! "Programmers need to make a living somehow." In the short run, this is true. However, there are plenty of ways that programmers could make a living without selling the right to use a program. This way is customary now because it brings programmers and businessmen the most money, not because it is the only way to make a living. It is easy to find other ways if you want to find them. Here are a number of examples. A manufacturer introducing a new computer will pay for the porting of operating systems onto the new hardware. The sale of teaching, hand-holding and maintenance services could also employ programmers. People with new ideas could distribute programs as freeware, asking for donations from satisfied users, or selling hand-holding services. I have met people who are already working this way successfully. Users with related needs can form users' groups, and pay dues. A group would contract with programming companies to write programs that the group's members would like to use. All sorts of development can be funded with a Software Tax: Suppose everyone who buys a computer has to pay x percent of the price as a software tax. The government gives this to an agency like the NSF to spend on software development. But if the computer buyer makes a donation to software development himself, he can take a credit against the tax. He can donate to the project of his own choosing---often, chosen because he hopes to use the results when it is done. He can take a credit for any amount of donation up to the total tax he had to pay. The total tax rate could be decided by a vote of the payers of the tax, weighted according to the amount they will be taxed on. The consequences: * The computer-using community supports software development. * This community decides what level of support is needed. * Users who care which projects their share is spent on can choose this for themselves. In the long run, making programs free is a step toward the post-scarcity world, where nobody will have to work very hard just to make a living. People will be free to devote themselves to activities that are fun, such as programming, after spending the necessary ten hours a week on required tasks such as legislation, family counseling, robot repair and asteroid prospecting. There will be no need to be able to make a living from programming. We have already greatly reduced the amount of work that the whole society must do for its actual productivity, but only a little of this has translated itself into leisure for workers because much nonproductive activity is required to accompany productive activity. The main causes of this are bureaucracy and isometric struggles against competition. Free software will greatly reduce these drains in the area of software production. We must do this, in order for technical gains in productivity to translate into less work for us.