PHP Weather - a METAR Decoder
*****************************

This is the definitive guide to PHP Weather, or at least it tries to
be. PHP Weather is a script written in PHP (http://www.php.net/) which
makes it possible to display the current weather on a webpage. The
system is based on data from 4,500 airports scattered all over the
world, so there is a good chance that you will find a station near your
place.

Table of Contents
*****************


PHP Weather - a METAR Decoder

Introduction

Installation
  Installation Details

Configuration
  The `defaults.php' file
  Choosing a Database Backend
  Required Functions in a Backend

Using PHP Weather
  Output Modules
    Changing the Output
  The Raw Data

Translating PHP Weather
  Diverse Translations

Things To Do

History

Contributors

Licenses
  GNU General Public License
    Appendix: How to Apply These Terms to Your New Programs
  GNU Free Documentation License
    ADDENDUM: How to use this License for your documents

Concept Index


Introduction
************

PHP Weather is script written in PHP (http://www.php.net/) that can
decode a METAR. A "METAR"(1) is a weather report used for avionic
purposes -- it has information about the temperature, the wind speed
and direction, the clouds, the current weather phenomena, and so on.
The information is presented in a special coded format, a format which
PHP Weather can decode.

   The METAR reports are made at about 4,500 airports from around the
world, so there is a good chance that you live near one of them. And
the airports make an report once or twice an hour, so you will be able
to provide fresh reports on your website.

   The reports from all over the world are stored at the National
Weather Service (the "NWS", see `http://www.nws.noaa.gov/') which is a
department under the National Oceanic and Atmospheric Administration
("NOAA", see `http://www.noaa.gov/') of the United States.  The reports
are available using both HTTP and FTP -- PHP Weather uses HTTP because
it is the fastest of the two protocols.

   Once you have got hold of a METAR, you will want to display the
weather report contained within it. A textual display, known as a
"pretty print" looks like this:

     This is a report for _Aalborg, Denmark_. The report was made _33_
     minutes ago, at _21:50_ UTC. The wind was blowing at a speed of
     _2.1_ meters per second (_4.6_ miles per hour) from _east_
     (_100_). The temperature was _16_C (_61_ F), with a dew-point
     at _15_ C (_59_ F). The atmospheric pressure was _1017_ hPa
     (_30.03_ inHg). The relative humidity was _93.8%_. There were no
     clouds below _1524_ meter (_5000_ feet) and no cumulonimbus
     clouds. The overall visibility was greater than _10_ kilometers
     (_6.2_ miles).


   Each station is uniquely identified by it is "ICAO" code. ICAO is an
abbreviation for the International Civil Aviation Organization
(http://www.icao.org/).

   You can control the output in various ways:

   * You can change the HTML markup that is inserted before and after
     each value in the report. Using `<b>' and `</b>' gives you bold
     letters whereas `<font color="navy">' and `</font>' gives you
     navy-blue colored text. The choice is yours, see *Note Changing
     the Output::.

   * You can change the language of the report. The report is built by
     combining many tiny strings which can be translated into other
     languages. There is also support for more diverse translations, see
     *Note Diverse Translations::.


   Instead of text, you can also have PHP Weather select icons for you
that match the current weather conditions.

   ---------- Footnotes ----------

   (1) The abbreviation METAR is a French abbreviation for "message
d'observation mtorologique rgulire pour l'aviation" which roughly
translates to English as "Aviation Routine Weather Report".

Installation
************

PHP Weather has been designed so that it is easy to install it. After
you have obtained PHP Weather, just unpack it somewhere on your
webserver and load the file `index.php' in your favorite browser.

   The next section will give you more details.

Installation Details
====================

The first thing to do, is to get hold of PHP Weather. The official PHP
Weather homepage can be reached at `http://phpweather.net/' and you
will be able to download the latest version of PHP Weather from the
"Downloads" section.

   After you have downloaded PHP Weather in your favorite format (we
provide files in three formats: `tar.gz', `tar.bz2', and `zip') you
should unpack it in a temporary place. If the file you downloaded is
called `phpweather-x.y.tar.gz', then it will be unpacked in a directory
called `phpweather-x.y'. Upload this directory with all its files to
your webserver.

   PHP Weather has now been installed! Use your browser to load the file
`index.php' found in the root-directory of the PHP Weather installation
and see how it works. You will be presented with a demonstration of PHP
Weather.

Configuration
*************

Although PHP Weahter works right out of the package, you should
configure it before you start to use it on your frontpage.

The `defaults.php' file
=======================

The behaviour of PHP Weather is controlled by several things. All
options have default values, but they can be changed in several places.
The value of an option is found by this process:

  1. The file `defaults-dist.php' in the root-directory of the PHP
     Weather installation is read using `include'. This defines the
     initial values of the options.

  2. Next, the file `defaults.php' is read if it exists. This file is
     not part of the PHP Weather distribution, but should be created by
     you if you want to change some of the defaults from
     `defaults-dist.php'.

  3. You can supply an array when you create an object from the PHP
     Weather codebase. The following code will create a `phpweather'
     object with the ICAO set to `EKAH':

          $weather = new phpweather(array('icao' => 'EKAH'));

     You can (of course) change several options at the same time, the
     general template for this is

          $weather = new phpweather(array('OPTION-1' => `value-1',
                                          'OPTION-2' => `value-2',
                                          ...,
                                          'OPTION-N' => `value-n'));

  4. You can change some of the options after you have created the
     object. If you want to change the current ICAO of a `phpweather'
     object, then you will use the `set_icao' method like this:

          $weather->set_icao('EKYT');


   The idea is, that you should create a `defaults.php' file with the
options that you will always want to use -- things like database and
proxy settings. To create the file, you should use the supplied script
`make_config.php' found in the `config' directory.

   Load the script in the browser and follow the instructions. In short,
then you build the configuration file by repeatedly choosing/changing
options until the all say "Input accepted". You will notice that all
options are at their default settings when you load the page initially
-- you will have to change something and press the "Update Options"
button before anything changes.

   When you press the button, the page will reload, and the
configuration file found at the bottom is updated with your new
selections. Also, your selection might give your more choices such as
when you change the `use_proxy' option from "No" to "Yes". When you
press the update button you will be presented with input fields for the
`proxy_host' and the `proxy_port'. Because we cannot anticipate the
name of your proxy, the `proxy_host' will be set to nothing (the empty
string "") initially. Since this is not a valid hostname, you will see
a text in red that says exactly this.

   Continue to make changes to the options. When you are happy with the
configuration you should press the "Download the Configuration" button.
Your browser should ask you where to same the downloaded file -- save
it as `defaults.php' in the root of your PHP Weather installation.

   All new objects created will now start out with the options in this
file. This means that you can store sensitive things like database
passwords in just one location, instead of having it scattered through
out all the scripts that use PHP Weather. Just remember to protect the
`defaults.php' file itself if you put your password in it!

Choosing a Database Backend
===========================

PHP Weather works by retrieving weather reports called METARs. It takes
some time to get the METARs, so you will be interested in using a local
database as a cache. All database backends support the same features
(see *Note Required Functions in a Backend:: for details) but differ in
speed. Your version of PHP might also lack support for some of the
backends. PHP Weather supports the following databases backends:

`null'
     This is the default "database" backend, but it is not really a
     database. It pretends to cache the METARs, but in reallity it just
     throws them away. This means that PHP Weather will have to fetch
     them from the NWS again each time.

     This makes the `null' backend the slowest backend if you repeadaly
     need the same METAR, e.g. if you show the current weather for a
     fixed location on your homepage. But it is just as quick (or slow,
     depending on how you view things) as the other backends when it
     comes to showing the weather for a random station. So if that is
     your typical usage-pattern, then you might like this backend.

`pw_mysql'
     You can use the MySQL (http://www.mysql.com/) relational database
     with PHP Weather.

`pw_pgsql'
     You can also choose to use a PostgreSQL (http://postgresql.org/)
     database.

`pw_dba'
     This database backend uses normal files on the webserver to do the
     caching. You will have to ensure that the PHP process on the
     webserver can write to the `db/files' directory so that the
     necessary files can be created and maintained.


   After you have chosen a database backend, you will have to initialize
the database. You should first generate the appropriate `defaults.php'
file, see *Note The defaults.php file::.

   After you have uploaded the file to the webserver, you can load the
script `make_db.php' found in the `config' directory in your favorite
browser. When you press the "Create or Recreate Tables" button the
database will be initialized.  If you have selected a SQL-based
database, then the necessary tables will be created.

   If you have selected a file-based database, then the script will
attempt to create the necessary files. This might very well fail: the
script is run by the webserver, and the webserver will most likely _not_
have permission to create new files in the `db/files' directory under
the PHP Weather root directory because the webserver runs as an
unprivileged user.

   So, you will have to change the permission on the `db/files'
directory.  Assuming that the webserver is running some form of Unix
and that you have shell access to the machine, then you can execute the
following commands after you have logged into the webserver.  If you do
not have that kind of access to the machine, then you should still be
able to change the permissions using your FTP program.  The relevant
commands are:

     cd /root/directory/of/phpweather/installation
     chmod 777 db/files
     chmod 777 db/files/*

   Everybody will now be allowed to create and change files under the
`db/files' directory. *This is a security risk!* If you know of a
better way to allow the webserver read/write access to the files,
please use that instead and tell us so that we can update the manual.

Required Functions in a Backend
===============================

All database backends have to support a common set of methods -- if PHP
had support for _interfaces_, then we would require them to implement a
database interface.  Because of the lack of interfaces in the PHP
language we are left with this description of what a database backend
has to satisfy.

   All database backends are defined in their own class which is a
subclass of the `pw_db_common' class. If we pretend that we have a
`pw_db_foo' database backend, then it must implement the following
methods:

 - Method on pw_db_foo: get_type
     This should return the type of the backend, `foo' in our case.

 - Method on pw_db_foo: connect
     This is called by every other method that wants to ensure that the
     database is up and running. The method should cache the result of
     this operation as it will be called several times.

 - Method on pw_db_foo: disconnect
     This disconnects from the database.

 - Method on pw_db_foo: insert_metar $station $metar $timestamp
     Inserts a METAR into the database.

Using PHP Weather
*****************

Now that you have learned about how to install and configure PHP
Weather, you might want to learn how you can use it on your own
webpages.

Output Modules
==============

The textual output you have seen on the `index.php' demonstration page
is produces by an "output module" called `pw_text'. The images are
selected by another module called `pw_images'.

   These modules illustrate the idea behind PHP Weather: the code in
`phpweather.php' handles the parsing of the METAR and then someone else
has to present the data in a meaningful way.

Changing the Output
-------------------

You can change the output of PHP Weather.

The Raw Data
============

It is easy for you to get hold of the raw data produced by the code in
`phpweather.php':

     $weather = new phpweather();
     $data = $weather->decode_metar();

   The variable `$data' is now an multidimensional associative array
filled with all the information that the `decode_metar' function was
able to extract from the METAR. The different parts in the METAR is
stored under specific keys in the array -- if the METAR lacks a given
part, then the corresponding entry in the array will be left out.  This
means that you will have to check each entry with the built-in PHP
function `empty' before you use it, otherwise you see warnings from
PHP, if you have set the error reporting level high enough.

   You can have PHP show you the structure of the array by using the
builtin `print_r' function like this:

     echo "<pre>\n";
     print_r($data);
     echo "</pre>\n";

   The following entries is always part of a METAR report, and is
therefore always part of the decoded METAR array:

`type'
     This can either be `METAR' or `SPECI' and denotes the type of the
     report.  This is not used for anything.

`metar'
     The raw METAR report.

`icao'
     The ICAO of the station which made the report.

`location'
     The English name of the station.

`time'
     A UNIX timestamp corresponding to the time of the report.


   The following entries are all optional so check with `empty' before
accessing them:

`report_mod'
     A report modifier which gives information about how the report was
     made: `AUTO' for a fully automated report with no human
     intervention or `COR' for a corrected report. It is supposed to be
     part of all METARs, but experience shows that it is not.

`wind'
     This is an array with information about the wind. The `deg' entry
     tells you the direction of the wind as compass-direction. If the
     wind came from variable directions, then will be the string `VRB'.

     The `meters_per_second', `miles_per_hour', and `knots' entries
     tells you the wind speed in various units.

     If gust was observed, there will be three extra entries:
     `gust_meters_per_second', `gust_miles_per_hour', and `gust_knots'.

     If the wind was varying, then two extra entries are present:
     `var_beg' and `var_end'. Both of these entries contain a
     compass-direction

`visibility'
     This is an array with visibility information. Each entry in the
     array is a separate visibility group.

     Each visibility group contains a `prefix' which can be `-1', `0',
     or `1' which tells you if the visibility reported is "less than",
     "normal", or "greater than" respectively.

     The visibility itself is stored in the `meter', `km', `ft', and
     `miles' entries. There is an optional entry `dir' for a direction
     -- if there is no direction, then the visibility refers to the
     overall visibility.

`runway'
     This is an array of runway groups. Each entry is a separate group.

     The groups contain an `nr' entry and an optional `approach' entry
     which tells you the runway-number and the approach respectively.
     The approach is one of `L', `C', or `R' for "left", "center", or
     "right" respectively.

     The visibility information can either be a single value or a pair
     of values in case of varying conditions. If there is only a single
     value, then `meter' and `ft' holds the visibility, an optional
     `prefix' can be `-1' if range is less than the lowest reportable
     value or `1' if greater than the greatest reportable value. A
     `tendency' entry holds either `D', `N' or `U' for "downward
     tendency", "no distinct tendency", or "upward tendency"
     respectively.

`weather'
     This holds the current weather phenomena and is one of the most
     interesting groups. It is an array of weather groups which means
     that the the first group will be `$data['weather'][0]', the second
     group (if there is such a group) will be `$data['weather'][1]',
     and so on.

     Each group contains a `proximity' entry which can be either `VC'
     for phenomena in the vicinity or the empty string otherwise.

     Next comes the `intensity'. This can be `-' for light phenomena,
     the empty string for moderate phenomena, or `+' for heavy
     phenomena.

     This is followed by a `descriptor', a `precipitation', a
     `obscuration', and finally a `other' entry. These entries contain
     the actual data found in the METAR. This means that it's up to the
     application to decode these symbols further, so that `RA' becomes
     "rain" and so on.

`clouds'
     This is an array of cloud groups. Each group has a `condition'
     entry which can be either `CAVOK' for no clouds and no significant
     weather, `VV' for "vertical visibility", `FEW' for "few clouds",
     `SCT' for "scattered clouds", `BKN' for "broken clouds", `OVC' for
     "overcast", and `SKC' and `CLR' for "clear sky". The condition
     `CAVOK' is a bit special, because if it is present, then the
     `condition' entry will be the only entry in the cloud group.

     The other conditions will be part of a larger array with an
     optional `cumulus' entry denoting the presence of cumulonimbus
     (`CB') or towering cumulus (`TCU') clouds. There will also be
     `meter' and `ft' entries with the height of the clouds. If the
     clouds are below the station, then the height will be stored as
     `nil'. Theres an optional `prefix' with the usual meaning.

`temperature'
     This is the temperature group. It is an array with two or four
     entries: `temp_c' and `temp_f' is always present and is the
     temperature in degrees Celsius and Fahrenheit respectively. If
     information about the dew-point is present, then `dew_c' and
     `dew_f' will be added to the array.

`temp_min_max'
     Some stations report the minimum and maximum temperature over
     various timescales. The temperatures are stored in `min6h_c',
     `min6h_f', `max6h_c' and `max6h_f' for the temperatures in the
     last 6 hours, and in `min24h_c', `min24h_f', `max24h_c' and
     `max24h_f' for the temperatures in the last 24 hours.

`altimeter'
     This is the air pressure measured in various units. The array has
     these entries: `inhg', `mmhg', `hpa', and `atm'.

`precipitation'
     This is an array which stores the precipitation measured over
     various timescales. The entries `mm' and `in' contains the
     precipitation during the last hour, entries `mm_h6' and `in_6h'
     store the amount of precipitation in the last 3-6 hours and
     finally there is `mm_24h' and `in_24h' with the precipitation
     measured over the last 24 hours. If there has been snowfall, then
     that will be reported in the `snow_mm' and `snow_in' entries.

     All the entries can contain the special value `-1' which means
     that there was only a trace of precipitation.

`remarks'
     Anything which is not recognized is added to this entry.


Translating PHP Weather
***********************

You can translate PHP Weather into other languages that the ones
provided in the package you downloaded.

Diverse Translations
====================

PHP Weather has facilities ready that makes it possible to totally
redefine the generated text from within a translation.

Things To Do
************

PHP Weather is a work in progress -- it will probably never be finished
because people seams to have a never-ending thirst for new features.

   This an attempt to list some of the things that PHP Weather might do
in the future:

   * Parse Terminal Aearodome Forecasts (TAF) reports. These reports
     are similar to METAR reports, the difference is that they contain
     _forecasts_ instead of just the current weather. This is of course
     much more interesting that the current weather conditions.

     There is more information about how to decode TAF reports at this
     website: `http://www.awc-kc.noaa.gov/awc/help/taf-decode.html'.

   * Improve the system used to select units. It would be nice, if the
     user could choose a unit for each element displayed instead of
     just having to choose between metric and imperial units.

   * Add support for other timezones than UTC so that people can say
     that they want the time reported in their local timezone.

   * Have PHP Weather calculate the time of sunset and -rize
     automatically based on latitude and longitude data for the
     stations.  This information would be used to select correct
     sun/moon images.

   * It should be possible to calculate the local time for a given
     station based on the same geographical data combined with data
     about local daylight saving times.


History
*******

I began writing PHP Weather in June 2000. I had been talking with
Kristian Kristensen <zianet@zianet.dk> about making such a script for a
project we were both working on. But it was only after the project was
finished, that I began investigating the possibilities of making a
script with PHP that could display the current weather.

   I knew that it was possible to do such a thing, as I had seen a
couple of applets (small programs that serves only one purpose, such as
displaying the time or the amount of free space on the hard drive,
etc.) that could display the weather. I discovered that they got their
data from the NWS who makes the data available at no cost.

   The data is available off the Internet via either FTP or HTTP, so it
is easy to get hold of it with PHP. The only problem was that the data
has to be decoded because it is written in a compact fashion. The data
in question is a so-called METAR report that the airports issue once or
twice an hour.

   I then discovered a script written in Perl that could take a METAR
and split it into its components. The script was written by Jeremy D.
Zawodny <Jeremy@Zawodny.com> and is licensed under the GPL just like
PHP Weather. So there was no problem with me peeping at his code for
PHP Weather. I took the logic from the Perl script and wrote a function
in PHP that would decode a METAR.

   But that would not do it -- to be useful the decoded data has to be
displayed in a nice fashion, preferable so that it is easy to
customize. The script should also be able to fetch a METAR from the NWS
and once that is done, the METAR should be cached so that the script
would run faster after the METAR had been fetched once. The problem is,
that it takes about a second to contact the NWS.

   I wanted to see the data I could extract from the METAR in a
meaningfull way, so I started wrapping the data in English words to
form sentences like in "The temperature is 20 degrees Celsius (68
degrees Fahrenheit)". That turned out very nice so I released the code
to the public.

   I did not think about internationalization then, but after a while, I
received a Spanish translation made by Eduardo Guilenea.  Because the
script was not ready for internationalization, he had simply gone
through the script and translated all the English words into Spanish.

   That promped me to start thinking about how we could translate PHP
Weater into other languages. I quickly found out, that it would work if
we kept the strings used in external files instead of having them in
the main `phpweather.inc' file. The users could then simply use
`include(locale_da.inc)' to get Danish output.

   As things started to grow, it became apparent that PHP Weather would
have to be reorganized. I wanted a more flexible structure, a structure
that would allow us to extend PHP Weather in the future without having
to mess with the code that does the actually parsing of the METARs. We
also had to be able to support databases in a cleaner way -- the code
in `phpweather.inc' had turned into a mess.

   So I started to split the file up into several files, and also
started to use classes in PHP. This was the first time I had to do an
object oriented design, so it was very exciting.

   The result is the current PHP Weather, and it does have a quite
flexible structure. All locale-specific code has been moved out from
the main parsing algorithms, so that PHP Weather can be truly
localized. All access to the database is now done through a database
abstraction layer: each database is defined in its own class, so it is
free to implement the various methods any way it wants.

Contributors
************

Everybody listed below has helped in some way with the creation of PHP
Weather.  If, by some mistake, your name isn't listed below, then send
a mail to Martin Geisler <gimpster@gimpster.com> so that proper credit
can given.  Please include your SourceForge login, if any, and an URL
if you like.

Kristian Kristensen (kkrz)
     He made the interface to PostgreSQL.

Jeremy D. Zawodny
     He wrote `Geo::METAR', which is a Perl module which can do some of
     the things PHP Weather now does. `Geo::METAR' can be found here:
     `http://www.wcnet.org/jzawodn/perl/Geo-METAR/index.html'.

Enrico Lodolo
     For suggesting that I use http to get the METARs instead of the
     much slower ftp.

Stefan Wiesendanger
     For rewritting some large `case'- and `switch'-statements as a
     couple of arrays. This speeds-up the parsing of the METARs.

Mike
     He noticed that the pressures was all wrong. I though the unit
     used in the METAR was hPa, when it really was inHg.

Jeffrey Y. Sue
     Suggested that I told people how to turn off the warnings, if you
     don't establish a connection to MySQL.

     Later he made it possible to use PHP Weather with DBM databases. He
     also added support for precipitation. Lots of other stuff, see the
     `ChangeLog' for more details.

Rutger Lubbers
     Noticed that South/southeast was duplicated in the
     directions-array.

Eduardo Guilenea
     Translated PHP Weather into Spanish, and thereby forced me to add
     support for multiply languages. (Which was a Good Thing :-)

Sven-Erik (seasoft)
     Translated PHP Weather into Norwegian.

     He also sat down and did the boring work, when he manually compiled
     the complete list of all airports available from NWS.

Maciek Uhlig
     Noticed that I sometimes tried to access `$cloud_coverage_array'
     with just `$cloud_coverage' -- which, of cause, didn't work.

Ing. Vladimir Kotala
     Suggested that I changed the long text `... degrees Celsius' into
     the more compact `... C', which is much better.

Gyulai Mihly (misibacsi) `http://gyulai.freeyellow.com/'
     Made the Hungarian translation for PHP Weather. He has also
     corrected tons of spelling errors.

Johnny Funder <jhf@naviair.dk>
     Lots of explanations and suggestions. He also gave a much simpler
     formula for calculating the relative humidity.

Ray van Beek
     Helped me spot a little error with the current weather. He has also
     written code that displays the current weather as an image.

David Kjellquist
     Added support for windchill.

Max Hammond (iridium)
     Lots of different things: bugfixes, clever suggestions, and general
     maintenance.

Jess Peas
     Made the Spanish translation.

Ondrej Jombik (nepto)
     Translated PHP Weather into Slovak and rewrote the navigation
     system used in index.php. He also looked at the MySQL and
     PostgreSQL database and found some security flaws.

Reini Urban
     Fixed some problems with using PHP Weather on a default
     installation of PHP 4.2.

Kari Salovaara and Tage Malmen
     Translated PHP Weater into Swedish and Finnish.

Paul Kairis
     Wrote the code that handles connections through a proxy server.

Bas Elshof
     Translated PHP Weather into Dutch.

Vclav Rkal
     Made a Czech translation.

Radoslava Fedkov
     Czech translation.

Guillaume Petit
     Translated PHP Weather into French.

Rudy Boedts
     Updated the Dutch translation.

Konrad Tadesse
     Finally, a working German translation.

Andrew Simpson (andrewsimpson)
     Reported problems with the use of short open tags in a couple of
     files.

Jim Whitehead
     Fixed the rounding of hours and minutes in the pretty-printed
     report.

Ferhat Bingol
     Made a Turkish translation.

Renato Gallmetzer
     Provided us with an Italian translation.

Pablo Alcaraz (pabloa)
     Updated the Spanish translation and other bugfixes.

Etienne Tourigny (etienne_t)
     Added a method that decodes TAF reports and made some of the
     database backends archive the data instead of always replacing the
     old data with new reports.

Justin Heideman
     Drew a full set of beautiful icons for PHP Weather to display the
     current weather conditions.

Warren Rohner
     Updated the South African stations in the `stations.csv' file.

Nick Crossland (ncrossland)
     Made a British English translation.

Jos de vila Junior
     Updated the Brazillian stations in the `stations.csv' file.

Cludio Gamboa
     Contributed a Portugues translation.


Licenses
********

Because we believe in Open Source (http://www.opensource.org/), we have
licensed the code in PHP Weather under the GNU General Public License
and the manual under the GNU Free Documentation License. This license
is similar to the GPL, it is just aimed for documentation.

   This means that you are allowed to use PHP Weather on as many
websites as you like, and you are even allowed to use it on commercial
websites.

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.

    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

Appendix: 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) YYYY  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) 19YY NAME OF AUTHOR
     Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `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.

GNU Free Documentation License
==============================

                        Version 1.1, March 2000
     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.

  0. PREAMBLE

     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.

     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 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".

     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.
     (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.

     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.

     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 "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".

     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.

     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.

  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 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 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.

     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 less than five).

       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", 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.

       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. In any section entitled "Acknowledgments" or "Dedications",
          preserve the section's title, and preserve in the section all
          the substance and tone of each of the contributor
          acknowledgments 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 as "Endorsements" or to
          conflict in title with any Invariant Section.

     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.

     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
     "Acknowledgments", 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, 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.

     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.

  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 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.

  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 1.1
       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''.

   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.

   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.

Concept Index
*************

advanced translations:
          See ``Diverse Translations''.
Backend, databases:
          See ``Choosing a Database Backend''.
Checking for new versions:
          See ``Installation Details''.
Choosing a database:
          See ``Choosing a Database Backend''.
Configuration:
          See ``Configuration''.
data, raw:
          See ``The Raw Data''.
Database backends, differences:
          See ``Choosing a Database Backend''.
database, functions:
          See ``Required Functions in a Backend''.
defaults.php, building:
          See ``The `defaults.php' file''.
distributing PHP Weather:
          See ``Licenses''.
diverse translations:
          See ``Diverse Translations''.
Downloading PHP Weather:
          See ``Installation Details''.
FDL, GNU Free Documentation License:
          See ``GNU Free Documentation License''.
future:
          See ``Things To Do''.
GPL, GNU General Public License:
          See ``GNU General Public License''.
history:
          See ``History''.
Installation:
          See ``Installation''.
Introduction:
          See ``Introduction''.
licens:
          See ``Licenses''.
Localization:
          See ``Translating PHP Weather''.
modules, output:
          See ``Output Modules''.
Obtaining PHP Weather:
          See ``Installation Details''.
output modules:
          See ``Output Modules''.
Output, changing <1>:
          See ``Changing the Output''.
Output, changing:
          See ``Output Modules''.
PHP Weather, configuration:
          See ``Configuration''.
PHP Weather, history:
          See ``History''.
PHP Weather, how to install <1>:
          See ``Installation Details''.
PHP Weather, how to install:
          See ``Installation''.
raw data:
          See ``The Raw Data''.
TODO list:
          See ``Things To Do''.
Translating:
          See ``Translating PHP Weather''.
translating, advanced:
          See ``Diverse Translations''.
usage:
          See ``Using PHP Weather''.
