2010-03-04 Zoltan Varga <vargaz@gmail.com>

[mono/afaerber.git] / web / mono-beginning.xml

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" []>
<article>

  <articleinfo>

    <!-- Use "HOWTO", "mini HOWTO", "FAQ" in title, if appropriate -->
    <title>Running Mono</title>


    <author>
       <firstname>Hinne</firstname>
       <surname>Hettema</surname>
       <affiliation>
          <address><email>h.hettema@auckland.ac.nz</email></address>
       </affiliation>
     </author>
    <author>
       <firstname>Jaime</firstname>
       <surname>Anguiano Olarra</surname>
       <affiliation>
          <address><email>jaime@genuara.ugr.es</email></address>
       </affiliation>
     </author>

     <pubdate>2002-06</pubdate>

     <!-- Most recent revision goes at the top; list in descending order -->
     <!-- All dates specified in ISO "YYYY-MM-DD" format -->
     <revhistory>
       <revision>
          <revnumber>0.1</revnumber>
          <date>2002-06-20</date>
          <authorinitials>HH</authorinitials>
          <revremark>First release</revremark>
       </revision>
     </revhistory>

     <!-- Provide a good abstract; a couple of sentences is sufficient -->
     <abstract>
        <para>
        This document describes how to install mono on your Linux system 
        from the source and describes some simple experiments you can
        perform with this installation.
        </para>
     </abstract>

  </articleinfo>


<sect1 id="intro">
<title>Introduction</title>

<para>
Mono is an open source implementation of the Common Language Infrastructure
(CLI) specified in ECMA standard 335. It comes with a C# compiler and
provides an extensible platform to develop and run applications that
are interoperable with Microsoft .NET.
</para>

<para>
Mono is not finished--it is a project still under development. As a
result, installation and configuration may not be as smooth as you
will be used to from other Linux applications. Nevertheless, mono is
in a state that will allow you to get it up and running and gain
experience with it--which is, I would suggest, a very smart thing to do.
</para>

<para>
This document is limited in the following sense: it describes how to
download a 'stable' version of mono as a 'tarball' and get it to run on
your computer. I'm also assuming you run mono on Linux rather than
on Windows. All the examples have been tested on a 'vanilla' Red Hat 7.3 
installation.
</para>

<para>
There are two items this document will <emphasis>not 
</emphasis> cover: the first is how to self host the mcs compiler 
under linux and the second is the graphical user environment 
which is implemented as GTK#. These two interesting topics 
are the subject of two more howto's that I'm planning.
</para>

<para>
This document is also less useful for two types of people.
</para> 
<itemizedlist> 
<listitem> 
<para> 
If you are a very inexperienced linux user and want to know what mono is
all about, there is an easier way to install mono. Go to mono.baselabs.org
and download the rpm's ready for installation on your system. This site also
runs a tutorial that is worth reading.
</para> 
</listitem> 
<listitem> 
<para> 
If you are a very experienced user wanting to contribute to the mono code,
you should probably regularly do a CVS download. At the moment, the mono
code grows very fast, and the 'stable' releases still appear too slowly.
</para>
</listitem>

</itemizedlist>

<para>
This document is aimed at the mono beginner, and aims to present a complete
view of a minimal installation, which will allow you to experiment with
mono to some degree. It also describes some of those experiments. We
expect that after reading this document you'll go on to do either of
two things:
</para>
<orderedlist>
<listitem>
<para>
Continue to contribute to the mono project in some shape or form. The
website has some ideas and suggestions under the heading 'Contributing'.
</para>
</listitem>
<listitem>
<para>
Continue to write applications that run in mono. 
</para>
</listitem>
</orderedlist>

<para>
We hope this document will be useful to you in your first steps with mono.
Happy hacking!
</para>

<sect2 id="note">
<title>A note on the development of this document</title>
<para>
This document is expected to grow into a full 'running mono howto' over time.
As of yet, it does not really discuss some of the excellent efforts of others
to package mono into an rpm or deb and prepare it for easy installation.
It is our aim to include this in future versions of this document.
</para>
</sect2>

<sect2 id="prerequisites">
<title>Prerequisites</title>
<para>
This document assumes you are somewhat familiar with the architecture
of the Common Language Infrastructure and the C# programming language.
</para>

<para>
To compile mono on your system, you will also have to satisfy 
some dependencies on other software. A list of these are given 
on the mono download page. Read through this list to see if 
you've got all components. 
</para>

<para>
On a practical note, I had no dependency issues with the 
installation of mono 0.12 on a 'standard issue' Red Hat 7.3 build.
</para>

</sect2>

<sect2 id="disclaimer"> <title>Disclaimer</title>

<para> 
No liability for the contents of this document can be accepted.
Use the concepts, examples and information at your own risk.  There may
be errors and inaccuracies, that could be damaging to your system.
Proceed with caution, and although this is highly unlikely, the author(s)
do not take any responsibility.  
</para>

<para> 
All copyrights are held by their by their respective owners,
unless specifically noted otherwise.  Use of a term in this document
should not be regarded as affecting the validity of any trademark or
service mark.  Naming of particular products or brands should not be
seen as endorsements.  
</para> 
</sect2>

<!-- Give credit where credit is due...very important --> <sect2
id="credits"> <title>Credits / Contributors</title>

<para> This document was originally created by Jaime Anguiano Olarra,
but has been extensively rewritten. Credits are due to </para>
<itemizedlist> 
<listitem> 
<para>Jaime Anguiano Olarra <email>jaime@geneura.ugr.es</email> 
for creating the original version of this document, and in fact 
the document that got me through installing mono for the first time.
</para> 
</listitem> 
<listitem>
<para>
My partner Margaret for support on my more exotic ventures.
</para>
</listitem>
</itemizedlist> 
</sect2>

<!-- Feedback --> 
<sect2 id="feedback"> <title>Feedback</title>

<para> 
Feedback is most certainly welcome for this document. Send your
additions, comments and criticisms to the following email address:
<email>mono-docs-list@ximian.com</email>. I am lurking on this list 
and will maintain this document as required.  
</para> 
</sect2>
</sect1>

<!-- This is the preamble stuff over with the rest of document
follows... --> 
<sect1 id="installation"> 
<title> Installing Mono</title>

<sect2 id="obtaining"> 
<title>Obtaining Mono</title> 
<para> 
There are several ways to get Mono running on your computer. This
document will discuss only one of those: downloading the source tarball
and utilising the make utilities to get mono up and running.  There is
only one mono package to worry about if you are just after a 'base' install
of mono: the mono runtime. This package, found under the name "mono-x.xx"
has got a compiled version of the compiler built in.
</para>

<para>
You'll be able to complete everything in this document if you just install
the runtime, but taking a look at the compiler package is well worth the
effort. The compiler is written in C# and is 'self hosting' which means it
is able to compile itself. 
</para>

<para>
As of this moment, it is my understanding that there are still some issues
with the 'self hosting' bit of the compiler on linux, although this is 
expected to work in later versions of mono. If you are just interested in
finding out how mono will work under linux, I would not worry about the
self-hosting bit for now. The self-hosting of the compiler will be the
topic of a future howto.
</para>

<para> 
See <ulink url="http://www.go-mono.com/download">the mono download
site</ulink> for the source of the tarballs.  
</para>

<para>
This page also lists the current versions of the software 
mono depends on. Make sure that your system has all the 
required versions, otherwise mono won't compile.
</para>

<para>
At a minimum for mono 0.12, you'll need to:
</para>

<itemizedlist>
<listitem>
<para>
download and install
<ulink url="http//www.freedesktop.org/software/pkgconfig">
pkg-config</ulink>.
</para>
</listitem>
<listitem>
<para>
download and install
<ulink url="ftp://ftp.gtk.org/pub/gtk/v1.3/glib-1.3.12.tar.gz">
glib 1.3</ulink>.
</para>
</listitem>
</itemizedlist>

<para> 
Installing the tarballs is done via GNU autoconf and
automake. The general upshot of running autoconf and automake is that you
can type <command>./configure</command> and then <command> make</command>
to do the build.  
Typing <command>make install</command> completes the installation of mono
on your system.
</para>

<para>
To build the mono runtime package, unzip the tarball to some useful
location.  I tend to use <command>/usr/src</command> as the location,
but you could really do it anywhere. For the install process, it is
also a good idea to be 'root'.  The installation process will shuttle
some executables into <command>/usr/local/bin</command> (more about
that later).
</para>

<para>
Unzipping the tarballs will have created two directories in <command>
/usr/src/</command>, one called something like mono-x.xx and the other 
mcs-x.xx. The one called 'mono' is the runtime environment, and this contains
all that is initially needed to run mono and investigate its inner workings.
</para>

<para>
To start building the mono runtime, first type <command>./configure</command>.
You will see an output like this:
</para>
<programlisting>
[root@taurus mono-0.12]# ./configure
loading cache ./config.cache
checking host system type... i686-pc-linux-gnu
checking target system type... i686-pc-linux-gnu
checking build system type... i686-pc-linux-gnu
checking for a BSD compatible install... (cached) /usr/bin/install -c
checking whether build environment is sane... yes
checking whether make sets ${MAKE}... (cached) yes
checking for working aclocal... found


snip ....


checking BASE_DEPENDENCIES_CFLAGS...  -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include
checking BASE_DEPENDENCIES_LIBS...  -lglib-2.0
checking for GC_malloc in -lgc... (cached) no
configure: warning: Compiling mono without GC.
checking if off_t is 64 bits wide... no
checking if _FILE_OFFSET_BITS=64 gives 64 bit off_t... ok

snip ...

creating Makefile
creating mono/Makefile
creating mono/utils/Makefile
creating mono/metadata/Makefile
creating mono/dis/Makefile
creating mono/cil/Makefile
creating mono/arch/Makefile
creating mono/os/Makefile
creating mono/os/win32/Makefile
creating mono/os/unix/Makefile
creating mono/arch/x86/Makefile
creating mono/arch/ppc/Makefile
creating mono/arch/sparc/Makefile
creating mono/arch/arm/Makefile
creating mono/interpreter/Makefile
creating mono/tests/Makefile
creating mono/benchmark/Makefile
creating mono/monoburg/Makefile
creating mono/monograph/Makefile
creating mono/jit/Makefile
creating mono/io-layer/Makefile
creating mono/handles/Makefile
creating runtime/Makefile
creating scripts/Makefile
creating man/Makefile
creating doc/Makefile
creating docs/Makefile
creating config.h
config.h is unchanged


        GC:     auto


[root@taurus mono-0.12]#
</programlisting>


<para>
This means that the configure script has now created all the 
makefiles necessary to complete the build on your system. 
Note the "GC: auto" at the end of the list of commands. 
GC stands for "garbage collection" and it
will be addressed in a later section of this document.
</para>
<para>
You are now ready to start the mono "build" process. To kick 
this off, you can type <command>make</command> at the 
command prompt. You'll see something like this:
</para>

<programlisting>
[root@taurus mono-0.12]# make
make  all-recursive
make[1]: Entering directory `/usr/src/mono-0.12'
Making all in mono
make[2]: Entering directory `/usr/src/mono-0.12/mono'
Making all in utils
make[3]: Entering directory `/usr/src/mono-0.12/mono/utils'
gcc -DHAVE_CONFIG_H -I. -I. -I../.. -I/usr/include/glib-2.0 
-I/usr/lib/glib-2.0/include   -I/usr/include/glib-2.0 
-I/usr/lib/glib-2.0/include   -I../.. -I../../mono   
-D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE   -g -Wall 
-Wunused -Wmissing-prototypes -Wmissing-declarations 
-Wstrict-prototypes  -Wmissing-prototypes -Wnested-externs 
-Wpointer-arith -Wno-cast-qual -Wcast-align -Wwrite-strings 
-c mono-hash.c

</programlisting>
<para>
and this will continue for a while. On my 1 GHz Duron with 256 MB of RAM the 
total build process takes about three minutes. All the terrible flags after gcc
have essentially been set by the configure script and there is no need to worry
about these.
</para>
<para>
To finally install mono, you can type <command>make install</command> 
to get a working version of mono. This command will copy the 
scripts that run the executables to a place where the operating system
will be ale to find them. This location is <command>/usr/local/bin</command>
on my system. 
</para>

</sect2>

<sect2 id="garbage_collection">
<title> Garbage Collection</title>
<para>
To make the mint interpreter work with garbage collection, you first need to
install a garbage collection package on your system. Mono works with
Boehm Garbage collection, which is found at 
<ulink url="http://www.hpl.hp.com/personal/Hans_Boehm/gc/">
http://www.hpl.hp.com/personal/Hans_Boehm/gc/
</ulink>.
</para>

<para>
To get garbage collection to work, I downloaded the source tarball 
into <command>/usr/src/</command> and typed <command>./configure</command>
followed by <command>make</command> and <command>make install</command>.
</para>

<para>
There is one glitch to work around. The header file for the garbage collection
<command>gc.h</command> is found in the <command>/usr/src/gc6.0/include
</command> directory (at least on my system). The mono build process will break
on this location: it is looking for the header file in some other place called
<command>/usr/include/gc/</command> and won't be able to find the correct
header file.
</para>

<para>
The solution is to build a symbolic link between these two locations as 
follows
</para>

<programlisting>
[root@taurus include]# ln -s /usr/src/gc6.0/include/ /usr/include/gc
</programlisting>

<para>
after which you'll be able to list the directory contents as if they were
in <command>/usr/include</command>
</para>

<programlisting>
[root@taurus include]# pwd
/usr/include
[root@taurus include]# ls /usr/include/gc
cord.h                gc_backptr.h  gc_inline.h             javaxfc.h
ec.h                  gc_cpp.h      gc_local_alloc.h        leak_detector.h
gc                    gc_gcj.h      gc_mark.h               new_gc_alloc.h
gc_alloc.h            gc.h          gc_pthread_redirects.h  private
gc_amiga_redirects.h  gc_inl.h      gc_typed.h              weakpointer.h
[root@taurus include]#
</programlisting>

<para>
To get mono to work with garbage collection, you'll have to rebuild the
environment. This is done easily by typing <command>make distclean</command>
to clean up any existing executables.
</para>

<para>
Continue the build by typing <command>./configure</command>, and look at
the last line. It should read:
</para>

<programlisting>

snip...

creating config.h


        GC:     boehm


[root@taurus mono-0.12]#

</programlisting>

<para>
The GC: boehm tells you that garbage collection has been turned on. Now to
compile the runtime, you type <command>make</command> and <command> make
install</command> as previously.
</para>

<para>
You now have mono working with Garbage Collection.
</para>

<para>
Although my experimentation is incomplete as of this time, I have found some
issues with running Garbage Collection continuously, and my recommendation
would be to turn it off for now.
</para>

<para>
To turn garbage collection off again, you have to go to the <command>/usr/src
</command> directory where you extracted the tarball. Enter the <command>gc6.0
</command> directory and type <command>make uninstall</command> to uninstall 
Garbage Collection. Then in your <command>mono</command> directory, type
<command>make distclean</command> followed by <command>./configure</command>,
<command>make</command> and <command>make install</command>.
</para>

</sect2>

</sect1>

<sect1 id="running">
<title>Running mono</title>
<sect2 id="basic">
<title>Basic steps</title>
<para>
To work with mono, you first have to create a C# program. Open up 
your favourite editor, and type in the following code:
</para>
<programlisting>
using System;

class Hello
{
public static void Main(String[] args)
        {
        Console.WriteLine("mono:: is alive and well...");

        for (int i = 0; i < args.Length; i++)
                Console.WriteLine("Argument {0} = {1}", i, args[i]);
        }
}
</programlisting>

<para>
Save the file as hello.cs. To compile this into a working program, 
type mcs hello.cs. If you get the following:
</para>
<programlisting>
[hinne@taurus hello]$ mcs hello.cs
RESULT: 0
[hinne@taurus hello]$
</programlisting>
<para>
you know the compile worked fine. If you see some strange error
messages including the word 'parser' somewhere, you made a mistake in
your program. Fix this up first.
</para>

<para>
You are now ready to execute your first mono program.  To execute 
the code, type
</para>

<programlisting>
[hinne@taurus hello]$ mono hello.exe arg1 arg2 arg 3
</programlisting>
<para>
(where we have given some arguments just for fun) and you'll 
see the following:
</para>

<programlisting>
mono:: is alive and well...
Argument 0 = arg1
Argument 1 = arg2
Argument 2 = arg
Argument 3 = 3
RESULT: 0
</programlisting>
<para>
As you can see, mono printed the line "mono:: is alive and well" 
and printed the list of arguments. This completes the creation 
and execution of your first mono program.
</para>
</sect2>

<sect2 id="interpreter">
<title>Interpreter</title>
<para>
But mono will allow you to do more. First of all, mono is the 
compiled mono execution environment which uses the Just in 
Time (JIT) compiler. Mono also comes with an interpreted 
environment, which can be accessed using the command 'mint' 
as follows
</para>
<programlisting>
[hinne@taurus hello]$ mint hello.exe arg1 arg 2
mono:: is alive and well...
Argument 0 = arg1
Argument 1 = arg
Argument 2 = 2
[hinne@taurus hello]$
</programlisting>
<para>
As you can see, it makes no difference to mono output which 
environment you use, but what happens under the hood is very 
different. If you use 'mono' as the command line tool, you 
call the 'production' execution environment which will read 
your portable executable (PE) file, and call the just in 
time (JIT) compiler to compile the PE code down to machine 
level code (in my case, an x86 architecture) after which 
it is executed.
</para>
<para>
If you use mint, the JIT is not used, and the PE code is 
interpreted into x86 instructions for execution. In fact, 
for our simple 'hello' mint is slightly faster. The point 
is that the JIT compiler will take some time to compile the 
code of our program and store it in some location in memory, 
but the subsequent execution of the code is faster with mono.
</para>
<para>

You can see what happens below (the thing to look for is the 
'user' time: 0.1 seconds with mono and 0.06 seconds with mint):

</para>
<programlisting>
[hinne@taurus hello]$ time mono hello.exe arg1 arg 2
mono:: is alive and well...
Argument 0 = arg1
Argument 1 = arg
Argument 2 = 2
RESULT: 0

real    0m0.575s
user    0m0.100s
sys     0m0.010s
[hinne@taurus hello]$ time mint hello.exe arg1 arg 2
mono:: is alive and well...
Argument 0 = arg1
Argument 1 = arg
Argument 2 = 2

real    0m0.545s
user    0m0.060s
sys     0m0.000s
[hinne@taurus hello]$
</programlisting>
<para>
After this simple run of mono, it is time to play with some options. 
I won't cover these in detail since there are quite a few, and also because
I assume you downloaded mono to hack it around in the first place. So
I'll leave some pointers.
</para>


<sect3 id="debugging">
<title>Debugging</title>
<para>
Mono supports a debugging option when you specify the "-d" flag while running
the runtime. Utilising this flag will get you a significant amount of output,
and it may be an idea to specify an output file as well. The interesting aspect
of this file is that it allows you to see to some extent (quite precisely,
actually) what the JIT compiler is up to.
</para>
</sect3>

<sect3 id="statistics">
<title>Statistics</title>
<para>
It is also possible to collect some runtime statistics on your program. These
will give you some idea of the resource utilisation of your program.
</para>
<programlisting>
[hinne@taurus hello]$ mono --stats hello.exe
mono:: is alive and well...
RESULT: 0
Mono Jit statistics
Compiled methods:       58
Methods cache lookup:   15
Method trampolines:     698
Basic blocks:           188
Max basic blocks:       15
Allocated vars:         238
Analyze stack repeat:   61
Compiled CIL code size: 2450
Native code size:       10167
Max code size ratio:    7.13 (FileStream::FlushBuffer)
Biggest method:         1016 (StreamWriter::Write)
Code reallocs:          27
Allocated code size:    22073
Inlineable methods:     17
Inlined methods:        22

Created object count:   18
Initialized classes:    127
Used classes:           37
Static data size:       288
VTable data size:       8292
</programlisting>
</sect3>

</sect2>

<sect2 id="ILAsm_code" >
<title>Inspecting IL Assembly code</title>
<para>
Mono also provides a small tool that will let you disassemble 
the executable (.exe) file so you can have a peek 
under the hood. This tool is monodis, and is run as 
follows:

</para>
<programlisting>
[hinne@taurus hello]$ monodis hello.exe
.assembly extern mscorlib
{
  .ver 0:0:0:0
}
.assembly 'hello'
{
  .hash algorithm 0x00008004
  .ver  0:0:0:0
}
  .class private auto ansi beforefieldinit Hello
        extends [mscorlib]System.Object
  {

    // method line 1
    .method public hidebysig  specialname  rtspecialname
           instance default void .ctor()  cil managed
    {
        // Method begins at RVA 0x20ec
        // Code size 7 (0x7)
        .maxstack 8
        IL_0000: ldarg.0
        IL_0001: call instance void System.Object::.ctor()
        IL_0006: ret
    } // end of method instance default void .ctor()

    // method line 2
    .method public static
           default void Main(string[] args)  cil managed
    {
        // Method begins at RVA 0x20f4
        .entrypoint
        // Code size 56 (0x38)
        .maxstack 5
        .locals init (
                int32   V_0,
                int32   V_1)
        IL_0000: ldstr "mono:: is alive and well..."
        IL_0005: call void System.Console::WriteLine(string)
        IL_000a: ldc.i4.0
        IL_000b: stloc.0
        IL_000c: ldloc.0
        IL_000d: ldarg.s 0
        IL_000f: ldlen
        IL_0010: clt
        IL_0012: brfalse IL_0037

        IL_0017: ldstr "Argument {0} = {1}"
        IL_001c: ldloc.0
        IL_001d: box [mscorlib]System.Int32
        IL_0022: ldarg.s 0
        IL_0024: ldloc.0
        IL_0025: ldelem.ref
        IL_0026: call void System.Console::WriteLine(string, object, object)
        IL_002b: nop
        IL_002c: ldloc.0
        IL_002d: ldc.i4.1
        IL_002e: add
        IL_002f: stloc.1
        IL_0030: ldloc.1
        IL_0031: stloc.0
        IL_0032: br IL_000c

        IL_0037: ret
    } // end of method default void Main(string[] args)

  } // end of type Hello

[hinne@taurus hello]$
</programlisting>
<para>
This is the listing of the code of your program in a language 
called IL assembly, or Common Intermediate Language (CIL). The 
CIL provides the portability of the mono platform, and ensures 
that code compiled with Microsoft's .NET framework will work 
on mono and vice versa. 
</para>
</sect2>

<sect2 id="man_pages">
<title>Man pages</title>

<para>
Mono has man pages already installed, and generally, typing <command>
man</command> before the command you wish to execute should help in 
getting a list of the options. In many cases, it's still up to you
to figure out what they do.
</para>

</sect2>


</sect1>


<sect1 id="problems">
<title>Problems</title>
<para> 
With mono being as new as it is, it is likely that you will have some
problems with installation. The following are some ideas to help you
out in a bind:
</para>

<orderedlist>
<listitem>
<para> 
See the Ximian Bugzilla page to find out if there is a bug
report about your specific issue.
</para>
</listitem>

<listitem>
<para>Read this document.  If it does not solve your problem, we want to
know about it. Please send a message to the email address listed for
feedback at the beginning of the document.</para>
</listitem>

<listitem>

<para> 
Visit the mono mailing lists' archives and do a little
research in there for threads talking about the problem you have.
</para>
</listitem>

<listitem>
<para> 
If you still cannot correct the problem, send a message to the
mono list. When you do this, please be as precise as possible--i.e.
mention the system you are running, the version of mono that you have the 
problem with, and give any error codes and other output that might appear.
</para>
</listitem>
</orderedlist>

</sect1>

<sect1 id="knownproblems">
<title>Known Problems</title>

<para> mcs fails to compile in Linux.
To the best of my knowledge, as of yet mcs cannot compile in Linux. 
Try to install the already made packages from 
http://mono.baselabs.org/index.php/software. </para>
</sect1>

<!-- Legal Sections --> <sect1 id="copyright">
 <title>Copyright and License</title>

 <!-- The LDP recommends, but doesn't require, the GFDL --> <para>
     This document, <emphasis>Running mono</emphasis>, is copyrighted
     (c) 2002 by <emphasis>Hinne Hettema</emphasis> and
     <emphasis>Jaime Anguiano Olarra</emphasis>.  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 no Invariant
     Sections, with no Front-Cover Texts, and with no Back-Cover Texts.
     A copy of the license is included in the section entitled "GNU Free
     Documentation License".
 </para>

<sect2 id="gfdl"> <title>GNU Free Documentation License</title> 
<!-- GNU Project - Free Software Foundation (FSF) -->

<para>Version 1.1, March 2000</para>

<blockquote> <para>Copyright (C) 2000  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.</para> </blockquote>

<sect3 id="gfdl-0"> <title>PREAMBLE</title>

<para>The purpose of this License is to make a manual, textbook,
    or other written 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.</para>

<para>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.</para>

<para>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.</para>
</sect3>

<sect3 id="gfdl-1"> <title>APPLICABILITY AND DEFINITIONS</title>

<para>This License applies to any manual or other work that
    contains a notice placed by the copyright holder saying it can be
    distributed under the terms of this License.  The "Document", below,
    refers to any such manual or work.  Any member of the public is a
    licensee, and is addressed as "you".</para>

<para>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.</para>

<para>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.  (For example, 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.</para>

<para>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.</para>

<para>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.</para>

<para>A "Transparent" copy of the Document means a
    machine-readable copy, represented in a format whose specification
    is available to the general public, whose contents can be viewed and
    edited directly and 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
    has been designed to thwart or discourage subsequent modification
    by readers is not Transparent.  A copy that is not "Transparent"
    is called "Opaque".</para>

<para>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 designed for human modification.  Opaque formats include
    PostScript, PDF, 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 produced by some word processors for output
    purposes only.</para>

<para>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.</para>
</sect3>

<sect3 id="gfdl-2"> <title>VERBATIM COPYING</title>

<para>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.</para>

<para>You may also lend copies, under the same conditions stated
    above, and you may publicly display copies.</para>
</sect3>

<sect3 id="gfdl-3"> <title>COPYING IN QUANTITY</title>

<para>If you publish printed copies 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.</para>

<para>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.</para>

<para>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 publicly-accessible computer-network location containing
    a complete Transparent copy of the Document, free of added material,
    which the general network-using public has access to download
    anonymously at no charge using public-standard network protocols.
    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.</para>

<para>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.</para>
</sect3>

<sect3 id="gfdl-4"> <title>MODIFICATIONS</title>

<para>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:</para>

<orderedlist numeration="upperalpha"> <listitem><para>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.</para>
</listitem>

<listitem><para>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 less than five).</para>
</listitem>

<listitem><para>State on the Title page
      the name of the publisher of the Modified Version, as the
      publisher.</para>
</listitem>

<listitem><para>Preserve all the
      copyright notices of the Document.</para>
</listitem>

<listitem><para>Add an appropriate
      copyright notice for your modifications adjacent to the other
      copyright notices.</para>
</listitem>

<listitem><para>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.</para>
</listitem>

<listitem><para>Preserve in that license
      notice the full lists of Invariant Sections and required Cover
      Texts given in the Document's license notice.</para>
</listitem>

<listitem><para>Include an unaltered
      copy of this License.</para>
</listitem>

<listitem><para>Preserve the section
      entitled "History", and 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.</para>
</listitem>

<listitem><para>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.</para>
</listitem>

<listitem><para>In any section entitled
      "Acknowledgements" or "Dedications", preserve the section's title,
      and preserve in the section all the substance and tone of each
      of the contributor acknowledgements and/or dedications given
      therein.</para>
</listitem>

<listitem><para>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.</para>
</listitem>

<listitem><para>Delete any section
      entitled "Endorsements".  Such a section may not be included in
      the Modified Version.</para>
</listitem>

<listitem><para>Do not retitle any
      existing section as "Endorsements" or to conflict in title with
      any Invariant Section.</para>
</listitem> </orderedlist> <para>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.</para>

<para>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.</para>

<para>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.</para>

<para>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.</para>
</sect3>

<sect3 id="gfdl-5"> <title>COMBINING DOCUMENTS</title>

<para>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.</para>

<para>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.</para>

<para>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."</para>
</sect3>

<sect3 id="gfdl-6"> <title>COLLECTIONS OF DOCUMENTS</title>

<para>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.</para>

<para>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.</para>
</sect3>

<sect3 id="gfdl-7"> <title>AGGREGATION WITH INDEPENDENT WORKS</title>
<para>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, does not as a whole count
    as a Modified Version of the Document, provided no compilation
    copyright is claimed for the compilation.  Such a compilation is
    called an "aggregate", and this License does not apply to the other
    self-contained works thus compiled with the Document, on account
    of their being thus compiled, if they are not themselves derivative
    works of the Document.</para>

<para>If the Cover Text requirement of section 3 is applicable to
    these copies of the Document, then if the Document is less than
    one quarter of the entire aggregate, the Document's Cover Texts
    may be placed on covers that surround only the Document within
    the aggregate.  Otherwise they must appear on covers around the
    whole aggregate.</para>
</sect3>

<sect3 id="gfdl-8"> <title>TRANSLATION</title>

<para>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 provided that you also include the
    original English version of this License.  In case of a disagreement
    between the translation and the original English version of this
    License, the original English version will prevail.</para>
</sect3>

<sect3 id="gfdl-9"> <title>TERMINATION</title> <para>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.</para>
</sect3>

<sect3 id="gfdl-10"> <title>FUTURE REVISIONS OF THIS LICENSE</title>

<para>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 <ulink
    url="http://www.gnu.org/copyleft/">http://www.gnu.org/copyleft/</ulink>.</para>

<para>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.</para>
</sect3>

<sect3 id="gfdl-11"> <title>How to use this License for your
documents</title>

<para>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:</para>

<blockquote><para> 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 1.1 or any later version published by the Free Software
      Foundation; with the Invariant Sections being LIST THEIR TITLES,
      with the Front-Cover Texts being LIST, and with the Back-Cover
      Texts being LIST.  A copy of the license is included in the section
      entitled "GNU Free Documentation License".
</para></blockquote>

<para>If you have no Invariant Sections, write "with no Invariant
    Sections" instead of saying which ones are invariant.  If you
    have no Front-Cover Texts, write "no Front-Cover Texts" instead of
    "Front-Cover Texts being LIST"; likewise for Back-Cover Texts.</para>

<para>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.</para>
</sect3> </sect2> </sect1>

</article>