This is guile-gnome-tutorial.info, produced by makeinfo version 4.8
from guile-gnome-tutorial.texi.

INFO-DIR-SECTION The Algorithmic Language Scheme
START-INFO-DIR-ENTRY
* guile-gnome: (guile-gnome-tutorial).   An introduction to guile-gnome.
END-INFO-DIR-ENTRY
   Copyright (C) 2001 Martin Baulig Copyright (C) 2003,2004 Andy Wingo

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation License,
     Version 1.1 or any later version published by the Free Software
     Foundation;

     with the Invariant Sections being:

     "The GNU General Public License"          "The GNU Free
     Documentation License"

     and no Front-Cover Texts or Back-Cover Texts.

     You can find more information about this license, and the license
     of guile-gnome itself, at the end of the manual.

   This tutorial is for guile-gnome (version 2.15.90, last updated
12 September 2004), a binding between the Guile extension language and
the Gnome programming environment.


File: guile-gnome-tutorial.info,  Node: Top,  Next: The GLib type system,  Prev: (dir),  Up: (dir)

guile-gnome Tutorial
********************

   Copyright (C) 2001 Martin Baulig Copyright (C) 2003,2004 Andy Wingo

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation License,
     Version 1.1 or any later version published by the Free Software
     Foundation;

     with the Invariant Sections being:

     "The GNU General Public License"          "The GNU Free
     Documentation License"

     and no Front-Cover Texts or Back-Cover Texts.

     You can find more information about this license, and the license
     of guile-gnome itself, at the end of the manual.

* Menu:

* The GLib type system::        The foundations.
* Gtk+ Gdk Pango Atk::          An introduction to some guile-gnome
                                wrapsets.
* CORBA::                       Using CORBA from Scheme.

* The GNU General Public License::
* The GNU Free Documentation License::
 --- The Detailed Node Listing ---

The GLib type system

* Basic types::
* Enums and flags::
* Closures::
* GType::
* GObject::
* Deriving your own GObject types::

Gtk+, Gdk, Pango, Atk

* hello world::
* hello world improved::

CORBA

* Bootstrapping your IDL::
* Calling CORBA Methods::
* Implementing CORBA servants::
* Implementing CORBA servants - multiple inheritance::
* Implementing CORBA servants - an important limitation::
* CORBA structs / sequences::


File: guile-gnome-tutorial.info,  Node: The GLib type system,  Next: Gtk+ Gdk Pango Atk,  Prev: Top,  Up: Top

1 The GLib type system
**********************

One key part of GLib is `libgobject', an implementation of a runtime,
dynamic type system for C. Besides providing an object system to C, its
main design goal was to increase the ease with which C code can be
wrapped by interpreted languages, such as Guile or Perl.

   Guile's wrapper is implemented by the module `(gnome gobject)'.  Go
ahead and open up a Guile session and load it up:

     guile> (use-modules (gnome gobject))

   We will leave off the `guile>' prompt in the rest of this tutorial.
When we want to show the value of an expression, we use =>:

     (+ 3 5)
     => 8

   Make some coffee, and let's dig in.

* Menu:

* Basic types::
* Enums and flags::
* Closures::
* GType::
* GObject::
* Deriving your own GObject types::


File: guile-gnome-tutorial.info,  Node: Basic types,  Next: Enums and flags,  Prev: The GLib type system,  Up: The GLib type system

1.1 Basic types
===============

When communicating with `libgobject', most values need to be
strictly-typed. There is a type class corresponding to each basic type
in C: `<gchar>', `<guchar>', `<gboolean>', `<gint>', `<guint>',
`<glong>', `<gulong>', `<gint64>', `<guint64>', `<gfloat>', `<gdouble>',
and `<gchararray>'.

   You can make instances of these class with `make':

     (make <gboolean> #:value #f)
     => #<gvalue <gboolean> 40529040 #f>

     (make <guint> #:value 85)
     => #<gvalue <guint> 4054f040 85>

     (make <gfloat> #:value 3.1415)
     => #<gvalue <gfloat> 40556af0 3.1414999961853>

     (make <gchararray> #:value "Hello World!")
     => #<gvalue <gchararray> 4055af90 Hello World!>

   You can get the normal Scheme values back with `gvalue->scm':

     (gvalue->scm (make <gchararray> #:value "Hello World!"))
     => "Hello World!"


File: guile-gnome-tutorial.info,  Node: Enums and flags,  Next: Closures,  Prev: Basic types,  Up: The GLib type system

1.2 Enums and flags
===================

Enumerated values and bitflags are an essential part of many C APIs,
and so they are specially wrapped in the GLib type system. You can
create new enumerated types in Scheme by subclassing `<genum>':

     (define-class <foo> (<genum>)
       #:vtable '#((hello "Hello World" 1) (test "Test" 2)))

   Instances are created with `make', just like with the other types:

     (make <foo> #:value 'hello)
     (make <foo> #:value "Hello World")
     (make <foo> #:value 1)

     ;; These three all do the same thing
     => #<gvalue <foo> 406275f8 (hello Hello World 1)>

   If there's an already existing enum or flags class, you can get
information about it:

     (genum-class->value-table <foo>)
     => #((hello "Hello World" 1) (test "Test" 2))

   Enums and flags have a special representation on the Scheme side. You
can convert them to Scheme values as symbols, names, or as a numeric
value.

     (define foo (make <foo> #:value 'hello))
     (genum->symbol foo)
     => hello
     (genum->name foo)
     => "Hello World"
     (genum->value foo)
     => 1


File: guile-gnome-tutorial.info,  Node: Closures,  Next: GType,  Prev: Enums and flags,  Up: The GLib type system

1.3 Closures
============

Another data type provided by `libgobject' is the closure, an
abstraction for callable objects. The actual object is a function in
some language, be it C, Scheme, or even Python. You can create a
closure in Guile with `make' (again):

     (define (times-eight x)
       (* x 8))

     (define closure (make <gclosure> #:return-type <gint>
                       #:param-types (list <gulong>)
                       #:func times-eight))

     (gclosure-invoke closure 10)
     => 80

   The closure you create can then be passed to a C function, so that
any C function (even those that know nothing about Guile) can call back
into Scheme.


File: guile-gnome-tutorial.info,  Node: GType,  Next: GObject,  Prev: Closures,  Up: The GLib type system

1.4 GType
=========

All of the types that GLib knows about are available to Guile,
regardless of which language defined them. GLib implements this via a
type system, where every type has a name. So if you make a type called
"Foo" in C, you can get to it in Scheme via `gtype-from-name' and
`gtype->class':

     ;; Retrieve the type for the foo enum we made earlier in the tutorial
     (define foo-type (gtype-from-name "Foo"))
     (define <foo> (gtype->class foo-type))

     (make <foo> #:value 2)
     => #<gvalue <foo> 40535e50 (test Test 2)>


File: guile-gnome-tutorial.info,  Node: GObject,  Next: Deriving your own GObject types,  Prev: GType,  Up: The GLib type system

1.5 GObject
===========

`<gobject>' (`GObject' in C) is the basic object type in `libgobject'.
`(gnome gobject)' allows you to access existing GObject types, as well
as to create new GObject types in Scheme.

   Before we start, let's pull in some generic functions that reduce the
amount of typing we have to do:

     (use-modules (gnome gobject generics))

   Let's assume we start with `<gtk-window>' from `(gnome gtk)'.  The
keyword arguments to `make' are interpreted as GObject properties to
set:

     (define window (make <gtk-window>
                      #:type 'toplevel #:title "Hello, World!"))

   You can connect to signals on the new instance:

     (connect window 'delete-event
              (lambda (window event)
                ;; Returns #t to ignore this event
                #t))

     ;; connect is a generic function implemented by
     ;; gtype-instance-signal-connect

   And get and set properties...

     (get window 'title)
     => "Hello, World!"
     (set window 'resizable #f)

     ;; get and set are also generics, implemented by gobject-get-property
     ;; and gobject-set-property


File: guile-gnome-tutorial.info,  Node: Deriving your own GObject types,  Prev: GObject,  Up: The GLib type system

1.6 Deriving your own GObject types
===================================

You can create new GObject types directly from Scheme, deriving either
from a C object type or one you made in Scheme. Properties and signals
for the class, if any, should be set when you derive the class, not
afterwards.

     ;; deriving from <gobject>
     (define-class <test> (<gobject>)
       ;; a normal object slot
       my-data

       ;; an object slot exported as a gobject property
       (pub-data #:param-spec (list <gparam-long> #:name 'test))

       ;; a signal with no arguments and no return value
       #:signal '(frobate #f))

     ;; deriving from <test> -- also inherits properties and signals
     (define-class <hungry> (<test>))

   Adding a signal automatically defines the default method:

     ;; This is the default handler for this signal.
     (define-method (test:frobate (object <test>))
       (format #t "Frobating ~A\n" object))

     ;; We can override it for subclasses
     (define-method (test:frobate (object <hungry>))
       (next-method) ;; chain up
       (format #t "I'm hungry\n"))

     (emit (make <hungry>) 'frobate)
     ;; Try it!

   You can override the `initialize', `gobject:get-property', and
`gobject:set-property' methods. For an extended example, see
`tic-tac-toe.scm' in the `examples/gtk' directory of the distribution.


File: guile-gnome-tutorial.info,  Node: Gtk+ Gdk Pango Atk,  Next: CORBA,  Prev: The GLib type system,  Up: Top

2 Gtk+, Gdk, Pango, Atk
***********************

* Menu:

* hello world::
* hello world improved::


File: guile-gnome-tutorial.info,  Node: hello world,  Next: hello world improved,  Prev: Gtk+ Gdk Pango Atk,  Up: Gtk+ Gdk Pango Atk

2.1 `hello world'
=================

The following code can be found in `examples/gtk/hello.scm'. If you get
confused, make sure you've read the previous chapter.

     ;; Load up Gtk+ -- also pulls in GOOPS bindings
     (use-modules (gnome gtk))

     ;; Define the app as a function -- there are many other ways to do this,
     ;; of course...
     (define (app)
       ;; Every widget has a class. Here we make a window and a button.
       (let* ((window (make <gtk-window> #:type 'toplevel))
     	 (button (make <gtk-button> #:label "Hello, World!")))

         ;; There are scheme functions corresponding to all of the c ones...
         ;; and of course we don't have to cast anything.
         (gtk-container-set-border-width window 10)
         (gtk-container-add window button)

         ;; Attaching a lambda to a signal :-)
         (gobject-signal-connect button 'clicked (lambda (b) (gtk-main-quit)))

         (gtk-widget-show-all window)

         (gtk-main)))

     (app)


File: guile-gnome-tutorial.info,  Node: hello world improved,  Prev: hello world,  Up: Gtk+ Gdk Pango Atk

2.2 `hello world', improved
===========================

There's something about this that resembles programming in C a little
bit too much. In Python, you can just do `window.add(button)'.  That's
a lot less typing. In GOOPS, the object framework for Guile, methods
are implemented a bit differently. `(gnome gtk)' defines methods for
those Gtk+ functions described with `define-method' in the `.defs'
file. If we use these methods, `hello-generics.scm' looks a bit
different:

     (use-modules (gnome gtk))

     (define (app)
       (let* ((window (make <gtk-window> #:type 'toplevel))
     	 (button (make <gtk-button> #:label "Hello, World!")))

         ;; Since window is a container, this generic maps onto the function
         ;; gtk-container-set-border-width
         (set-border-width window 10)

         ;; Note that we can set the border width with a gobject property as
         ;; well:
         (gobject-set-property window 'border-width 15)

         ;; (gnome gobject generics), re-exported by (gnome gtk), defines a
         ;; generic `set' method for gobject-set-property, se we can also do
         ;; it like this:
         (set window 'border-width 20)

         ;; This is much less typing :-)
         (add window button)

         ;; See (gnome gobject generics) for a full list of gobject generic
         ;; functions
         (connect button 'clicked (lambda (b) (gtk-main-quit)))

         ;; Generic functions for .defs apis are defined in the .defs files,
         ;; not manually
         (show-all window)

         (gtk-main)))

     (app)

   More docs needed here...


File: guile-gnome-tutorial.info,  Node: CORBA,  Next: The GNU General Public License,  Prev: Gtk+ Gdk Pango Atk,  Up: Top

3 CORBA
*******

*Note*: This file is from the 0.2.0 release notes. Somewhere between
then and 0.5.0, CORBA got broken (I suspect changes in ORBit2 to be at
fault). Presumably, fixing this would be trivial, but I don't know. I'm
not a CORBA guru.

   This module depends heavily on ORBit2 - the ORB which we use in
GNOME 2 - it doesn't work with any other ORB, but read the bootstraping
section below.

* Menu:

* Bootstrapping your IDL::
* Calling CORBA Methods::
* Implementing CORBA servants::
* Implementing CORBA servants - multiple inheritance::
* Implementing CORBA servants - an important limitation::
* CORBA structs / sequences::


File: guile-gnome-tutorial.info,  Node: Bootstrapping your IDL,  Next: Calling CORBA Methods,  Prev: CORBA,  Up: CORBA

3.1 Bootstrapping your IDL
==========================

ORBit2 is a CORBA 2.3 compliant ORB - and, of course, it's interoperable
with other ORBs.

   However, it's not very useful to have an opaque `<CORBA:Object>' in
scheme if you don't know anything about this object. It's also not very
useful if you can't write your own CORBA servants in scheme.

   Basically, there are two ways to solve this problem: parsing the IDL
at runtime or doing it the GNOME 2 way - loading a shared library which
contains all the necessary information from the IDL.

   Some of the core GNOME 2 libraries like Bonobo provide so called
"imodule" libraries which are installed in
`$(libdir)/<modulename>_imodule.la'.

   To create such a library for your own IDL, you need to run ORBit2's
IDL compiler, `orbit-idl', with the `--imodule' argument - see the
`demos/corba/' directory in this distribution for an example.

   NOTE: The rest of this section refers to the sample IDL which can be
found in `demos/corba/Foo.idl' in this distribution.

   Once you installed this library, you can read it in scheme by calling

     (corba-primitive-open-module "Foo")

   This creates all the GOOPS classes and methods you need.

   If there's a a CORBA interface `Foo::Hello', the bootstrap process
will create a GOOPS class `<Foo:Hello>' which serves as stub class and
another GOOPS class `<POA:Foo:Hello>' which serves as skeleton class.

   All stub classes are derived from `<CORBA:Object>' and their CORBA
class hierarchy is preserved in scheme.

   All skeleton classes are derived from `<PortableServer-ServantBase>'
and their CORBA class hierarchy is preserved as well.


File: guile-gnome-tutorial.info,  Node: Calling CORBA Methods,  Next: Implementing CORBA servants,  Prev: Bootstrapping your IDL,  Up: CORBA

3.2 Calling CORBA Methods
=========================

This section refers to the sample IDL in `demos/corba/Foo.idl' in this
distribution.

   To call a CORBA method, all you need to do is to invoke the
corresponding method in the stub class - let's assume `hello' is an
instance of the `<Foo:Hello>' class:

     (Foo:Hello:doHello hello) ; calls the CORBA method `Foo::Hello::doHello'
                               ; on the CORBA Object `hello'.

   So to call CORBA methods, you don't even need to know that it's
CORBA :-)

   Oh, by the way, the cool thing about CORBA and scheme is that you
don't need to worry about these annoying CORBA exceptions - since you
automatically get a scheme exception `corba-system-exception' /
`corba-user-exception'.


File: guile-gnome-tutorial.info,  Node: Implementing CORBA servants,  Next: Implementing CORBA servants - multiple inheritance,  Prev: Calling CORBA Methods,  Up: CORBA

3.3 Implementing CORBA servants
===============================

Well, I guess the interesting part is to implement CORBA servants in
scheme - so let's assume you want to write a servant for the
`Foo::Hello' interface.

   The first thing you need to do is to derive its POA class (as a
special "feature" you can also use the POA class directly to specify
the default behavior for all servants of this interface, see below):

     (define-class <hello> (<POA:Foo:Hello>))

   Then, you define methods:

     (define-method (Foo:Hello:doHello (hello <hello>))
       (display (list "Hello World!" hello)) (newline))

   If you call `(next-method)', the POA classes method will be run -
and the default is to throw a `CORBA::NO_IMPLEMENT' system exception.

   However, you can override this:

     (define-method (Foo:Bar:Baz:haveFun (object <POA:Foo:Bar:Baz>) a b)
       (display (list "Default Foo:Bar:Baz:haveFun handler!" a b))
       (newline))

   If you created all the methods, you can create servants and call
`corba-servant->reference' to get a `CORBA::Object' reference:

     (define servant (make <hello>))
     (define hello (corba-servant->reference servant))

   Now you have a CORBA Object `hello' (for guile, this is an instance
of the GOOPS class `<Foo:Hello>') and you can invoke methods on it:

     (Foo:Hello:doHello hello)

   Even if this looks like there's just a scheme method being called -
this is a "real" CORBA call - for scheme `hello' is a "normal" CORBA
Object.

   NOTE: Any CORBA Objects which you create in guile are "owned" by
guile's garbage collector - so make sure to `CORBA_Object_duplicate()'
in a C function before you store it somewhere !


File: guile-gnome-tutorial.info,  Node: Implementing CORBA servants - multiple inheritance,  Next: Implementing CORBA servants - an important limitation,  Prev: Implementing CORBA servants,  Up: CORBA

3.4 Implementing CORBA servants - multiple inheritance
======================================================

Like in C, you can also create servants for CORBA interfaces which are
derived from other interfaces:

     (define-class <maximum> (<hello> <POA:Foo:MaximumHello>))
     (define-method (Foo:Hello:doHello (hello <maximum>))
       (display (list "Hello Maximum World!" hello))
       (newline)
       (next-method))

     (define maximum-servant (make <maximum>))
     (define maximum (corba-servant->reference maximum-servant))

   This creates a new servant for the CORBA interface
`Foo::MaximumHello' which is derived from `Foo::Hello' and
`Foo::Bar::Baz' - this inheritance is reflected in scheme.

     ;; Calls method `Foo:Hello:doHello' in class <maximum> and then
     ;; in <hello> because of the (next-method).
     (Foo:Hello:doHello maximum)

     ;; Calls method `Foo:Bar:Baz:haveFun' in class <POA:Foo:Bar:Baz> -
     ;; the default handler.
     (Foo:Bar:Baz:haveFun maximum 1 2)

   Since we're using real CORBA calls, all of this also works for calls
which are coming "from the outside" - ie. from C or a remote process.


File: guile-gnome-tutorial.info,  Node: Implementing CORBA servants - an important limitation,  Next: CORBA structs / sequences,  Prev: Implementing CORBA servants - multiple inheritance,  Up: CORBA

3.5 Implementing CORBA servants - an important limitation
=========================================================

CORBA servants can be implemented either in C or in scheme - but you
cannot mix them - to make it clear, an example:

   In the example above, you learned how to create a CORBA servant for
the `Foo::MaximumHello' CORBA interface in scheme.

   Now let's assume you already have an implementation for the
`Foo::Hello' interface in C.

   Even if `Foo::MaximumHello' is derived from `Foo::Hello' - you
cannot use the `Foo::Hello' C implementation in scheme.

   This limitation may sound obvious, but it's not so obvious at all if
you're a bit familiar with CORBA. In C, you would normally expect to
have a `vepv' and a `epv' vector in a CORBA servant - and to be able to
poke around in the vepv to override methods.

   As an ORBit2 specific implementation details, servants which you
create from scheme don't have a `vepv' at all and the `epv' is not what
you'd expect - the `epv' entries are scheme vectors and not pointers to
C functions.

   _Implementation details:_

   This works because ORBit2 has a feature to call one single function
to marshal any calls on a CORBA object - the `impl_finder_func' and
`relay_call' fields in the class info (see ORBit2 source code for
details).

   This feature was explicitly added to ORBit2 to make it easy to use
from scripting languages - it'd be difficult to provide "normal" `epv'
entries for the scheme methods (you'd have to generate a C function at
runtime which also contains a data pointer somewhere - before we added
this feature to ORBit2 I was using weird assembler tricks here and it
was also using much more memory - about 40 more bytes / CORBA method).


File: guile-gnome-tutorial.info,  Node: CORBA structs / sequences,  Prev: Implementing CORBA servants - an important limitation,  Up: CORBA

3.6 CORBA structs / sequences
=============================

There's support to access CORBA structs / sequences from scheme
including a special record type for structs - see the `(gnome corba)'
module for details.

   That's it for the docs. They're not quite adequate - want to write
some more? <a href="../../../contact/">Contact us</a>!


File: guile-gnome-tutorial.info,  Node: The GNU General Public License,  Next: The GNU Free Documentation License,  Prev: CORBA,  Up: Top

Appendix A The GNU General Public License
*****************************************

guile-gnome is free software. You are free to give this software to
anyone you like, with or without modifications, under the conditions
outlined below.

     		    GNU GENERAL PUBLIC LICENSE
     		       Version 2, June 1991

      Copyright (C) 1989, 1991 Free Software Foundation, Inc.
          59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      Everyone is permitted to copy and distribute verbatim copies
      of this license document, but changing it is not allowed.

     			    Preamble

       The licenses for most software are designed to take away your
     freedom to share and change it.  By contrast, the GNU General Public
     License is intended to guarantee your freedom to share and change free
     software--to make sure the software is free for all its users.  This
     General Public License applies to most of the Free Software
     Foundation's software and to any other program whose authors commit to
     using it.  (Some other Free Software Foundation software is covered by
     the GNU Library General Public License instead.)  You can apply it to
     your programs, too.

       When we speak of free software, we are referring to freedom, not
     price.  Our General Public Licenses are designed to make sure that you
     have the freedom to distribute copies of free software (and charge for
     this service if you wish), that you receive source code or can get it
     if you want it, that you can change the software or use pieces of it
     in new free programs; and that you know you can do these things.

       To protect your rights, we need to make restrictions that forbid
     anyone to deny you these rights or to ask you to surrender the rights.
     These restrictions translate to certain responsibilities for you if you
     distribute copies of the software, or if you modify it.

       For example, if you distribute copies of such a program, whether
     gratis or for a fee, you must give the recipients all the rights that
     you have.  You must make sure that they, too, receive or can get the
     source code.  And you must show them these terms so they know their
     rights.

       We protect your rights with two steps: (1) copyright the software, and
     (2) offer you this license which gives you legal permission to copy,
     distribute and/or modify the software.

       Also, for each author's protection and ours, we want to make certain
     that everyone understands that there is no warranty for this free
     software.  If the software is modified by someone else and passed on, we
     want its recipients to know that what they have is not the original, so
     that any problems introduced by others will not reflect on the original
     authors' reputations.

       Finally, any free program is threatened constantly by software
     patents.  We wish to avoid the danger that redistributors of a free
     program will individually obtain patent licenses, in effect making the
     program proprietary.  To prevent this, we have made it clear that any
     patent must be licensed for everyone's free use or not licensed at all.

       The precise terms and conditions for copying, distribution and
     modification follow.
     
     		    GNU GENERAL PUBLIC LICENSE
        TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

       0. This License applies to any program or other work which contains
     a notice placed by the copyright holder saying it may be distributed
     under the terms of this General Public License.  The "Program", below,
     refers to any such program or work, and a "work based on the Program"
     means either the Program or any derivative work under copyright law:
     that is to say, a work containing the Program or a portion of it,
     either verbatim or with modifications and/or translated into another
     language.  (Hereinafter, translation is included without limitation in
     the term "modification".)  Each licensee is addressed as "you".

     Activities other than copying, distribution and modification are not
     covered by this License; they are outside its scope.  The act of
     running the Program is not restricted, and the output from the Program
     is covered only if its contents constitute a work based on the
     Program (independent of having been made by running the Program).
     Whether that is true depends on what the Program does.

       1. You may copy and distribute verbatim copies of the Program's
     source code as you receive it, in any medium, provided that you
     conspicuously and appropriately publish on each copy an appropriate
     copyright notice and disclaimer of warranty; keep intact all the
     notices that refer to this License and to the absence of any warranty;
     and give any other recipients of the Program a copy of this License
     along with the Program.

     You may charge a fee for the physical act of transferring a copy, and
     you may at your option offer warranty protection in exchange for a fee.

       2. You may modify your copy or copies of the Program or any portion
     of it, thus forming a work based on the Program, and copy and
     distribute such modifications or work under the terms of Section 1
     above, provided that you also meet all of these conditions:

         a) You must cause the modified files to carry prominent notices
         stating that you changed the files and the date of any change.

         b) You must cause any work that you distribute or publish, that in
         whole or in part contains or is derived from the Program or any
         part thereof, to be licensed as a whole at no charge to all third
         parties under the terms of this License.

         c) If the modified program normally reads commands interactively
         when run, you must cause it, when started running for such
         interactive use in the most ordinary way, to print or display an
         announcement including an appropriate copyright notice and a
         notice that there is no warranty (or else, saying that you provide
         a warranty) and that users may redistribute the program under
         these conditions, and telling the user how to view a copy of this
         License.  (Exception: if the Program itself is interactive but
         does not normally print such an announcement, your work based on
         the Program is not required to print an announcement.)
     
     These requirements apply to the modified work as a whole.  If
     identifiable sections of that work are not derived from the Program,
     and can be reasonably considered independent and separate works in
     themselves, then this License, and its terms, do not apply to those
     sections when you distribute them as separate works.  But when you
     distribute the same sections as part of a whole which is a work based
     on the Program, the distribution of the whole must be on the terms of
     this License, whose permissions for other licensees extend to the
     entire whole, and thus to each and every part regardless of who wrote it.

     Thus, it is not the intent of this section to claim rights or contest
     your rights to work written entirely by you; rather, the intent is to
     exercise the right to control the distribution of derivative or
     collective works based on the Program.

     In addition, mere aggregation of another work not based on the Program
     with the Program (or with a work based on the Program) on a volume of
     a storage or distribution medium does not bring the other work under
     the scope of this License.

       3. You may copy and distribute the Program (or a work based on it,
     under Section 2) in object code or executable form under the terms of
     Sections 1 and 2 above provided that you also do one of the following:

         a) Accompany it with the complete corresponding machine-readable
         source code, which must be distributed under the terms of Sections
         1 and 2 above on a medium customarily used for software interchange; or,

         b) Accompany it with a written offer, valid for at least three
         years, to give any third party, for a charge no more than your
         cost of physically performing source distribution, a complete
         machine-readable copy of the corresponding source code, to be
         distributed under the terms of Sections 1 and 2 above on a medium
         customarily used for software interchange; or,

         c) Accompany it with the information you received as to the offer
         to distribute corresponding source code.  (This alternative is
         allowed only for noncommercial distribution and only if you
         received the program in object code or executable form with such
         an offer, in accord with Subsection b above.)

     The source code for a work means the preferred form of the work for
     making modifications to it.  For an executable work, complete source
     code means all the source code for all modules it contains, plus any
     associated interface definition files, plus the scripts used to
     control compilation and installation of the executable.  However, as a
     special exception, the source code distributed need not include
     anything that is normally distributed (in either source or binary
     form) with the major components (compiler, kernel, and so on) of the
     operating system on which the executable runs, unless that component
     itself accompanies the executable.

     If distribution of executable or object code is made by offering
     access to copy from a designated place, then offering equivalent
     access to copy the source code from the same place counts as
     distribution of the source code, even though third parties are not
     compelled to copy the source along with the object code.
     
       4. You may not copy, modify, sublicense, or distribute the Program
     except as expressly provided under this License.  Any attempt
     otherwise to copy, modify, sublicense or distribute the Program is
     void, and will automatically terminate your rights under this License.
     However, parties who have received copies, or rights, from you under
     this License will not have their licenses terminated so long as such
     parties remain in full compliance.

       5. You are not required to accept this License, since you have not
     signed it.  However, nothing else grants you permission to modify or
     distribute the Program or its derivative works.  These actions are
     prohibited by law if you do not accept this License.  Therefore, by
     modifying or distributing the Program (or any work based on the
     Program), you indicate your acceptance of this License to do so, and
     all its terms and conditions for copying, distributing or modifying
     the Program or works based on it.

       6. Each time you redistribute the Program (or any work based on the
     Program), the recipient automatically receives a license from the
     original licensor to copy, distribute or modify the Program subject to
     these terms and conditions.  You may not impose any further
     restrictions on the recipients' exercise of the rights granted herein.
     You are not responsible for enforcing compliance by third parties to
     this License.

       7. If, as a consequence of a court judgment or allegation of patent
     infringement or for any other reason (not limited to patent issues),
     conditions are imposed on you (whether by court order, agreement or
     otherwise) that contradict the conditions of this License, they do not
     excuse you from the conditions of this License.  If you cannot
     distribute so as to satisfy simultaneously your obligations under this
     License and any other pertinent obligations, then as a consequence you
     may not distribute the Program at all.  For example, if a patent
     license would not permit royalty-free redistribution of the Program by
     all those who receive copies directly or indirectly through you, then
     the only way you could satisfy both it and this License would be to
     refrain entirely from distribution of the Program.

     If any portion of this section is held invalid or unenforceable under
     any particular circumstance, the balance of the section is intended to
     apply and the section as a whole is intended to apply in other
     circumstances.

     It is not the purpose of this section to induce you to infringe any
     patents or other property right claims or to contest validity of any
     such claims; this section has the sole purpose of protecting the
     integrity of the free software distribution system, which is
     implemented by public license practices.  Many people have made
     generous contributions to the wide range of software distributed
     through that system in reliance on consistent application of that
     system; it is up to the author/donor to decide if he or she is willing
     to distribute software through any other system and a licensee cannot
     impose that choice.

     This section is intended to make thoroughly clear what is believed to
     be a consequence of the rest of this License.
     
       8. If the distribution and/or use of the Program is restricted in
     certain countries either by patents or by copyrighted interfaces, the
     original copyright holder who places the Program under this License
     may add an explicit geographical distribution limitation excluding
     those countries, so that distribution is permitted only in or among
     countries not thus excluded.  In such case, this License incorporates
     the limitation as if written in the body of this License.

       9. The Free Software Foundation may publish revised and/or new versions
     of the General Public License from time to time.  Such new versions will
     be similar in spirit to the present version, but may differ in detail to
     address new problems or concerns.

     Each version is given a distinguishing version number.  If the Program
     specifies a version number of this License which applies to it and "any
     later version", you have the option of following the terms and conditions
     either of that version or of any later version published by the Free
     Software Foundation.  If the Program does not specify a version number of
     this License, you may choose any version ever published by the Free Software
     Foundation.

       10. If you wish to incorporate parts of the Program into other free
     programs whose distribution conditions are different, write to the author
     to ask for permission.  For software which is copyrighted by the Free
     Software Foundation, write to the Free Software Foundation; we sometimes
     make exceptions for this.  Our decision will be guided by the two goals
     of preserving the free status of all derivatives of our free software and
     of promoting the sharing and reuse of software generally.

     			    NO WARRANTY

       11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
     FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
     OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
     PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
     OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
     TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
     PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
     REPAIR OR CORRECTION.

       12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
     WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
     REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
     INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
     OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
     TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
     YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
     PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
     POSSIBILITY OF SUCH DAMAGES.

     		     END OF TERMS AND CONDITIONS
     
     	    How to Apply These Terms to Your New Programs

       If you develop a new program, and you want it to be of the greatest
     possible use to the public, the best way to achieve this is to make it
     free software which everyone can redistribute and change under these terms.

       To do so, attach the following notices to the program.  It is safest
     to attach them to the start of each source file to most effectively
     convey the exclusion of warranty; and each file should have at least
     the "copyright" line and a pointer to where the full notice is found.

         <one line to give the program's name and a brief idea of what it does.>
         Copyright (C) <year>  <name of author>

         This program is free software; you can redistribute it and/or modify
         it under the terms of the GNU General Public License as published by
         the Free Software Foundation; either version 2 of the License, or
         (at your option) any later version.

         This program is distributed in the hope that it will be useful,
         but WITHOUT ANY WARRANTY; without even the implied warranty of
         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
         GNU General Public License for more details.

         You should have received a copy of the GNU General Public License
         along with this program; if not, write to the Free Software
         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


     Also add information on how to contact you by electronic and paper mail.

     If the program is interactive, make it output a short notice like this
     when it starts in an interactive mode:

         Gnomovision version 69, Copyright (C) year  name of author
         Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
         This is free software, and you are welcome to redistribute it
         under certain conditions; type `show c' for details.

     The hypothetical commands `show w' and `show c' should show the appropriate
     parts of the General Public License.  Of course, the commands you use may
     be called something other than `show w' and `show c'; they could even be
     mouse-clicks or menu items--whatever suits your program.

     You should also get your employer (if you work as a programmer) or your
     school, if any, to sign a "copyright disclaimer" for the program, if
     necessary.  Here is a sample; alter the names:

       Yoyodyne, Inc., hereby disclaims all copyright interest in the program
       `Gnomovision' (which makes passes at compilers) written by James Hacker.

       <signature of Ty Coon>, 1 April 1989
       Ty Coon, President of Vice

     This General Public License does not permit incorporating your program into
     proprietary programs.  If your program is a subroutine library, you may
     consider it more useful to permit linking proprietary applications with the
     library.  If this is what you want to do, use the GNU Library General
     Public License instead of this License.


File: guile-gnome-tutorial.info,  Node: The GNU Free Documentation License,  Prev: The GNU General Public License,  Up: Top

Appendix B The GNU Free Documentation License
*********************************************

     		GNU Free Documentation License
     		  Version 1.2, November 2002


      Copyright (C) 2000,2001,2002  Free Software Foundation, Inc.
          59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      Everyone is permitted to copy and distribute verbatim copies
      of this license document, but changing it is not allowed.


     0. PREAMBLE

     The purpose of this License is to make a manual, textbook, or other
     functional and useful document "free" in the sense of freedom: to
     assure everyone the effective freedom to copy and redistribute it,
     with or without modifying it, either commercially or noncommercially.
     Secondarily, this License preserves for the author and publisher a way
     to get credit for their work, while not being considered responsible
     for modifications made by others.

     This License is a kind of "copyleft", which means that derivative
     works of the document must themselves be free in the same sense.  It
     complements the GNU General Public License, which is a copyleft
     license designed for free software.

     We have designed this License in order to use it for manuals for free
     software, because free software needs free documentation: a free
     program should come with manuals providing the same freedoms that the
     software does.  But this License is not limited to software manuals;
     it can be used for any textual work, regardless of subject matter or
     whether it is published as a printed book.  We recommend this License
     principally for works whose purpose is instruction or reference.


     1. APPLICABILITY AND DEFINITIONS

     This License applies to any manual or other work, in any medium, that
     contains a notice placed by the copyright holder saying it can be
     distributed under the terms of this License.  Such a notice grants a
     world-wide, royalty-free license, unlimited in duration, to use that
     work under the conditions stated herein.  The "Document", below,
     refers to any such manual or work.  Any member of the public is a
     licensee, and is addressed as "you".  You accept the license if you
     copy, modify or distribute the work in a way requiring permission
     under copyright law.

     A "Modified Version" of the Document means any work containing the
     Document or a portion of it, either copied verbatim, or with
     modifications and/or translated into another language.

     A "Secondary Section" is a named appendix or a front-matter section of
     the Document that deals exclusively with the relationship of the
     publishers or authors of the Document to the Document's overall subject
     (or to related matters) and contains nothing that could fall directly
     within that overall subject.  (Thus, if the Document is in part a
     textbook of mathematics, a Secondary Section may not explain any
     mathematics.)  The relationship could be a matter of historical
     connection with the subject or with related matters, or of legal,
     commercial, philosophical, ethical or political position regarding
     them.

     The "Invariant Sections" are certain Secondary Sections whose titles
     are designated, as being those of Invariant Sections, in the notice
     that says that the Document is released under this License.  If a
     section does not fit the above definition of Secondary then it is not
     allowed to be designated as Invariant.  The Document may contain zero
     Invariant Sections.  If the Document does not identify any Invariant
     Sections then there are none.

     The "Cover Texts" are certain short passages of text that are listed,
     as Front-Cover Texts or Back-Cover Texts, in the notice that says that
     the Document is released under this License.  A Front-Cover Text may
     be at most 5 words, and a Back-Cover Text may be at most 25 words.

     A "Transparent" copy of the Document means a machine-readable copy,
     represented in a format whose specification is available to the
     general public, that is suitable for revising the document
     straightforwardly with generic text editors or (for images composed of
     pixels) generic paint programs or (for drawings) some widely available
     drawing editor, and that is suitable for input to text formatters or
     for automatic translation to a variety of formats suitable for input
     to text formatters.  A copy made in an otherwise Transparent file
     format whose markup, or absence of markup, has been arranged to thwart
     or discourage subsequent modification by readers is not Transparent.
     An image format is not Transparent if used for any substantial amount
     of text.  A copy that is not "Transparent" is called "Opaque".

     Examples of suitable formats for Transparent copies include plain
     ASCII without markup, Texinfo input format, LaTeX input format, SGML
     or XML using a publicly available DTD, and standard-conforming simple
     HTML, PostScript or PDF designed for human modification.  Examples of
     transparent image formats include PNG, XCF and JPG.  Opaque formats
     include proprietary formats that can be read and edited only by
     proprietary word processors, SGML or XML for which the DTD and/or
     processing tools are not generally available, and the
     machine-generated HTML, PostScript or PDF produced by some word
     processors for output purposes only.

     The "Title Page" means, for a printed book, the title page itself,
     plus such following pages as are needed to hold, legibly, the material
     this License requires to appear in the title page.  For works in
     formats which do not have any title page as such, "Title Page" means
     the text near the most prominent appearance of the work's title,
     preceding the beginning of the body of the text.

     A section "Entitled XYZ" means a named subunit of the Document whose
     title either is precisely XYZ or contains XYZ in parentheses following
     text that translates XYZ in another language.  (Here XYZ stands for a
     specific section name mentioned below, such as "Acknowledgements",
     "Dedications", "Endorsements", or "History".)  To "Preserve the Title"
     of such a section when you modify the Document means that it remains a
     section "Entitled XYZ" according to this definition.

     The Document may include Warranty Disclaimers next to the notice which
     states that this License applies to the Document.  These Warranty
     Disclaimers are considered to be included by reference in this
     License, but only as regards disclaiming warranties: any other
     implication that these Warranty Disclaimers may have is void and has
     no effect on the meaning of this License.


     2. VERBATIM COPYING

     You may copy and distribute the Document in any medium, either
     commercially or noncommercially, provided that this License, the
     copyright notices, and the license notice saying this License applies
     to the Document are reproduced in all copies, and that you add no other
     conditions whatsoever to those of this License.  You may not use
     technical measures to obstruct or control the reading or further
     copying of the copies you make or distribute.  However, you may accept
     compensation in exchange for copies.  If you distribute a large enough
     number of copies you must also follow the conditions in section 3.

     You may also lend copies, under the same conditions stated above, and
     you may publicly display copies.


     3. COPYING IN QUANTITY

     If you publish printed copies (or copies in media that commonly have
     printed covers) of the Document, numbering more than 100, and the
     Document's license notice requires Cover Texts, you must enclose the
     copies in covers that carry, clearly and legibly, all these Cover
     Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
     the back cover.  Both covers must also clearly and legibly identify
     you as the publisher of these copies.  The front cover must present
     the full title with all words of the title equally prominent and
     visible.  You may add other material on the covers in addition.
     Copying with changes limited to the covers, as long as they preserve
     the title of the Document and satisfy these conditions, can be treated
     as verbatim copying in other respects.

     If the required texts for either cover are too voluminous to fit
     legibly, you should put the first ones listed (as many as fit
     reasonably) on the actual cover, and continue the rest onto adjacent
     pages.

     If you publish or distribute Opaque copies of the Document numbering
     more than 100, you must either include a machine-readable Transparent
     copy along with each Opaque copy, or state in or with each Opaque copy
     a computer-network location from which the general network-using
     public has access to download using public-standard network protocols
     a complete Transparent copy of the Document, free of added material.
     If you use the latter option, you must take reasonably prudent steps,
     when you begin distribution of Opaque copies in quantity, to ensure
     that this Transparent copy will remain thus accessible at the stated
     location until at least one year after the last time you distribute an
     Opaque copy (directly or through your agents or retailers) of that
     edition to the public.

     It is requested, but not required, that you contact the authors of the
     Document well before redistributing any large number of copies, to give
     them a chance to provide you with an updated version of the Document.


     4. MODIFICATIONS

     You may copy and distribute a Modified Version of the Document under
     the conditions of sections 2 and 3 above, provided that you release
     the Modified Version under precisely this License, with the Modified
     Version filling the role of the Document, thus licensing distribution
     and modification of the Modified Version to whoever possesses a copy
     of it.  In addition, you must do these things in the Modified Version:

     A. Use in the Title Page (and on the covers, if any) a title distinct
        from that of the Document, and from those of previous versions
        (which should, if there were any, be listed in the History section
        of the Document).  You may use the same title as a previous version
        if the original publisher of that version gives permission.
     B. List on the Title Page, as authors, one or more persons or entities
        responsible for authorship of the modifications in the Modified
        Version, together with at least five of the principal authors of the
        Document (all of its principal authors, if it has fewer than five),
        unless they release you from this requirement.
     C. State on the Title page the name of the publisher of the
        Modified Version, as the publisher.
     D. Preserve all the copyright notices of the Document.
     E. Add an appropriate copyright notice for your modifications
        adjacent to the other copyright notices.
     F. Include, immediately after the copyright notices, a license notice
        giving the public permission to use the Modified Version under the
        terms of this License, in the form shown in the Addendum below.
     G. Preserve in that license notice the full lists of Invariant Sections
        and required Cover Texts given in the Document's license notice.
     H. Include an unaltered copy of this License.
     I. Preserve the section Entitled "History", Preserve its Title, and add
        to it an item stating at least the title, year, new authors, and
        publisher of the Modified Version as given on the Title Page.  If
        there is no section Entitled "History" in the Document, create one
        stating the title, year, authors, and publisher of the Document as
        given on its Title Page, then add an item describing the Modified
        Version as stated in the previous sentence.
     J. Preserve the network location, if any, given in the Document for
        public access to a Transparent copy of the Document, and likewise
        the network locations given in the Document for previous versions
        it was based on.  These may be placed in the "History" section.
        You may omit a network location for a work that was published at
        least four years before the Document itself, or if the original
        publisher of the version it refers to gives permission.
     K. For any section Entitled "Acknowledgements" or "Dedications",
        Preserve the Title of the section, and preserve in the section all
        the substance and tone of each of the contributor acknowledgements
        and/or dedications given therein.
     L. Preserve all the Invariant Sections of the Document,
        unaltered in their text and in their titles.  Section numbers
        or the equivalent are not considered part of the section titles.
     M. Delete any section Entitled "Endorsements".  Such a section
        may not be included in the Modified Version.
     N. Do not retitle any existing section to be Entitled "Endorsements"
        or to conflict in title with any Invariant Section.
     O. Preserve any Warranty Disclaimers.

     If the Modified Version includes new front-matter sections or
     appendices that qualify as Secondary Sections and contain no material
     copied from the Document, you may at your option designate some or all
     of these sections as invariant.  To do this, add their titles to the
     list of Invariant Sections in the Modified Version's license notice.
     These titles must be distinct from any other section titles.

     You may add a section Entitled "Endorsements", provided it contains
     nothing but endorsements of your Modified Version by various
     parties--for example, statements of peer review or that the text has
     been approved by an organization as the authoritative definition of a
     standard.

     You may add a passage of up to five words as a Front-Cover Text, and a
     passage of up to 25 words as a Back-Cover Text, to the end of the list
     of Cover Texts in the Modified Version.  Only one passage of
     Front-Cover Text and one of Back-Cover Text may be added by (or
     through arrangements made by) any one entity.  If the Document already
     includes a cover text for the same cover, previously added by you or
     by arrangement made by the same entity you are acting on behalf of,
     you may not add another; but you may replace the old one, on explicit
     permission from the previous publisher that added the old one.

     The author(s) and publisher(s) of the Document do not by this License
     give permission to use their names for publicity for or to assert or
     imply endorsement of any Modified Version.


     5. COMBINING DOCUMENTS

     You may combine the Document with other documents released under this
     License, under the terms defined in section 4 above for modified
     versions, provided that you include in the combination all of the
     Invariant Sections of all of the original documents, unmodified, and
     list them all as Invariant Sections of your combined work in its
     license notice, and that you preserve all their Warranty Disclaimers.

     The combined work need only contain one copy of this License, and
     multiple identical Invariant Sections may be replaced with a single
     copy.  If there are multiple Invariant Sections with the same name but
     different contents, make the title of each such section unique by
     adding at the end of it, in parentheses, the name of the original
     author or publisher of that section if known, or else a unique number.
     Make the same adjustment to the section titles in the list of
     Invariant Sections in the license notice of the combined work.

     In the combination, you must combine any sections Entitled "History"
     in the various original documents, forming one section Entitled
     "History"; likewise combine any sections Entitled "Acknowledgements",
     and any sections Entitled "Dedications".  You must delete all sections
     Entitled "Endorsements".


     6. COLLECTIONS OF DOCUMENTS

     You may make a collection consisting of the Document and other documents
     released under this License, and replace the individual copies of this
     License in the various documents with a single copy that is included in
     the collection, provided that you follow the rules of this License for
     verbatim copying of each of the documents in all other respects.

     You may extract a single document from such a collection, and distribute
     it individually under this License, provided you insert a copy of this
     License into the extracted document, and follow this License in all
     other respects regarding verbatim copying of that document.


     7. AGGREGATION WITH INDEPENDENT WORKS

     A compilation of the Document or its derivatives with other separate
     and independent documents or works, in or on a volume of a storage or
     distribution medium, is called an "aggregate" if the copyright
     resulting from the compilation is not used to limit the legal rights
     of the compilation's users beyond what the individual works permit.
     When the Document is included in an aggregate, this License does not
     apply to the other works in the aggregate which are not themselves
     derivative works of the Document.

     If the Cover Text requirement of section 3 is applicable to these
     copies of the Document, then if the Document is less than one half of
     the entire aggregate, the Document's Cover Texts may be placed on
     covers that bracket the Document within the aggregate, or the
     electronic equivalent of covers if the Document is in electronic form.
     Otherwise they must appear on printed covers that bracket the whole
     aggregate.


     8. TRANSLATION

     Translation is considered a kind of modification, so you may
     distribute translations of the Document under the terms of section 4.
     Replacing Invariant Sections with translations requires special
     permission from their copyright holders, but you may include
     translations of some or all Invariant Sections in addition to the
     original versions of these Invariant Sections.  You may include a
     translation of this License, and all the license notices in the
     Document, and any Warranty Disclaimers, provided that you also include
     the original English version of this License and the original versions
     of those notices and disclaimers.  In case of a disagreement between
     the translation and the original version of this License or a notice
     or disclaimer, the original version will prevail.

     If a section in the Document is Entitled "Acknowledgements",
     "Dedications", or "History", the requirement (section 4) to Preserve
     its Title (section 1) will typically require changing the actual
     title.


     9. TERMINATION

     You may not copy, modify, sublicense, or distribute the Document except
     as expressly provided for under this License.  Any other attempt to
     copy, modify, sublicense or distribute the Document is void, and will
     automatically terminate your rights under this License.  However,
     parties who have received copies, or rights, from you under this
     License will not have their licenses terminated so long as such
     parties remain in full compliance.


     10. FUTURE REVISIONS OF THIS LICENSE

     The Free Software Foundation may publish new, revised versions
     of the GNU Free Documentation License from time to time.  Such new
     versions will be similar in spirit to the present version, but may
     differ in detail to address new problems or concerns.  See
     http://www.gnu.org/copyleft/.

     Each version of the License is given a distinguishing version number.
     If the Document specifies that a particular numbered version of this
     License "or any later version" applies to it, you have the option of
     following the terms and conditions either of that specified version or
     of any later version that has been published (not as a draft) by the
     Free Software Foundation.  If the Document does not specify a version
     number of this License, you may choose any version ever published (not
     as a draft) by the Free Software Foundation.


     ADDENDUM: How to use this License for your documents

     To use this License in a document you have written, include a copy of
     the License in the document and put the following copyright and
     license notices just after the title page:

         Copyright (c)  YEAR  YOUR NAME.
         Permission is granted to copy, distribute and/or modify this document
         under the terms of the GNU Free Documentation License, Version 1.2
         or any later version published by the Free Software Foundation;
         with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
         A copy of the license is included in the section entitled "GNU
         Free Documentation License".

     If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
     replace the "with...Texts." line with this:

         with the Invariant Sections being LIST THEIR TITLES, with the
         Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

     If you have Invariant Sections without Cover Texts, or some other
     combination of the three, merge those two alternatives to suit the
     situation.

     If your document contains nontrivial examples of program code, we
     recommend releasing these examples in parallel under your choice of
     free software license, such as the GNU General Public License,
     to permit their use in free software.



Tag Table:
Node: Top1040
Node: The GLib type system2555
Node: Basic types3460
Node: Enums and flags4462
Node: Closures5690
Node: GType6474
Node: GObject7134
Node: Deriving your own GObject types8391
Node: Gtk+ Gdk Pango Atk9869
Node: hello world10084
Node: hello world improved11213
Node: CORBA12932
Node: Bootstrapping your IDL13698
Node: Calling CORBA Methods15472
Node: Implementing CORBA servants16371
Node: Implementing CORBA servants - multiple inheritance18228
Node: Implementing CORBA servants - an important limitation19582
Node: CORBA structs / sequences21514
Node: The GNU General Public License21999
Node: The GNU Free Documentation License41802

End Tag Table
