GNU Enterprise - Developers Introduction
 
James Thompson
GNU: Enterprise Core Development Team
Derek Neighbors
GNU: Enterprise Core Development Team
Edited by
Derek Neighbors

GNU Enterprise - Developers Introduction
by James Thompson and Derek Neighbors
by 
Edited by Derek Neighbors
Published Wed Jul 5 21:58:52 MST 2000
Copyright © 2000 by Free Software Foundation
Copyright (c) 2000 Free Software Foundation
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".

Table of Contents
1. An Introduction for Developers	000
Introduction	000
Why?	000
Features	000
Examples	000
High Level Demo	000
Consultants	000
Templates/Packages	000
Categories	000
Standard	000
Extended	000
Unfriendly	000
Base Packages	000
Other Packages	000
Architecture	000
Back-end	000
Business Objects	000
Application	000
ICL	000
Tools	000
GNUe Forms	000
GNUe Reports	000
GEDI (GNU Enterprise Data Interface)	000
EWOK (Enterprise Wide Office Kommunication	000
GEAS (GNU Enterprise Administration System)	000
I. Appendixes	000
A. GNU General Public License	000
B. GNU Free Documentation License	000

List of Tables
1-1. Base Packages	000

Chapter 1. An Introduction for Developers
Introduction
 GNU Enterprise is a meta-project aimed at developing a complete enterprise level business environment. It will consist of tools to quickly build business applications. Several packages and modules will be available ready for out of the box use or readily available to extend or customize to your needs. There will be templates by industry type so you are only getting the base of what your industry type would use. 
Why?
Businesses seeking to move to digital processes often find themselves with limited options. They find themselves choosing between the following options.
 Purchase proprietary shrink-wrapped software 
 This option has many drawbacks which include but are not limited to. 
•	 The business is forced to adapt their processes to conform to the rigid requirements of the purchased software. 
•	 A single source for updates and maintenance. 
•	 Their fate is tied to that specific vendor. 
•	 Often such packages have high entry costs many small or new businesses can not readily afford. 
 Pay a consultant to create their software 
 This solution is better than a shrink-wrapped solution. The software is usually tailored to the exact business needs. It does have a few drawbacks however. The software is tied to a specific consultant or company, usually by copyright, in the same manner as shrink wrapped software. If the consultant closes down their business, their customers can be left without any means of support. If source code is not available the system can't be maintained. If the source code is available, a new consultant must be paid to learn the entire system before maintenance is possible. The unique nature of the system has left the business vulnerable. 
 Maintain an in-house programming team 
 This solution is better than paying a consultant if a business can afford the personnel needed to maintain the systems. But hiring only a single programmer leaves a business in the same position as with a consultant. Many smaller companies cannot afford several full-time programmers. The unique nature of the code requires all development and testing to be done in-house. Since the software isn't usually shared outside the business it doesn't get the levels of peer review needed to achieve the highest quality. 
 None of these solutions provide a business with the security and freedom they deserve. Often businesses find themselves making compromises in their business practices and paying large sums of money to vendors they don't particularly care for simply because they are "locked in" to a specific solution. 
 It doesn't need to be this way. 
Features
 Modular System Design 
GNU Enterprise objects are defined at application run-time. This allows a system to be easily and rapidly modified by end users without risk of compromising the core system. 
A technically savvy business owner can browse a list of modules from a library on the GNU Enterprise site. She can pick various packages and modules that are of interest, install them via a tool like RPM, check out their features, remove the ones she doesn't like, finish up her testing and go live. As new packages and modules become available she can add and remove them as she desires (within reason). She ends up with a system that is exactly to her liking w/o the expense of hiring a consultant to customize the system. 
To achieve maximum modularity and be all things to all people within reason, GNUe is looking at the following approach. GNUe will be a set of tools to build business applications. With these tools modules will be built. Modules will be bundled by similar function to create packages. One problem in doing this is the different needs of different industries. A doctor has a very different billing situation than car dealer ship for instance. Therefore, there will be "templates" by vertical industry if need be. The concept is GNUe->Packages->Modules->Components where components can be reused among modules. Modules are bundled by type ex: accounts recievable, accounts payable, general ledger are bundled in accounting package. Then multiple packages make up GNUe. Then each vertical industry can have specific templates if desired to make customization minimal from set up to setup. (Further documentation and flow charts coming on this subject.) 
 Open Architecture 
Every effort has been made to open the GNU Enterprise system to developers and users. CORBA provides a clean interface to the objects that comprise a functional GNU Enterprise system. All data is stored in a relational database system. The database structures are well documented and accessible via standard SQL. XML is used to define forms that are parsed and executed by a wide variety of clients. 
 Powerful Development Framework 
The base distribution of GNU Enterprise will contain several powerful tools. Tools like GNUE Forms, GNUE Reports, GEDI, GEAS and EWOK will allow developers to rapidly develop GNU Enterprise applications. 
 Consistency 
 Widespread deployment of GNU Enterprise will allow programmers to become familiar with the core GNU Enterprise components. They should require little time to get up to speed on a specific company's modifications to the code. This frees the programmer from learning the details of a unique system that is useless to them in other jobs. They can spend more time doing what they enjoy, writing code to solve unique problems. 
 Freedom from Single Source Vendors 
 A consultant can assure their customer that in the event they were unable to maintain the software it would be easy to find others familiar with the core system. This also provides the business some assurance that the consultant won't hold a monopoly on their systems, that they are free to let others work on their code. 
 Easy Maintenance 
 Since modules are used to store alterations to the system. Modifications made by the end site are stored separately from the generic distribution. Updates to the generic system can be applied without effecting local changes. Consultants need not maintain several virtually identical source trees with individual customer alterations, simple modules store all the changes. 
 Package Library 
 A person setting up an GNU Enterprise system would have access to growing number of packages for the system. These packages could be specialized for specific areas of business (manufacturing, legal, etc.) and would allow a programmer to produce a fairly specialized system in short period of time then tweak the system to meet the exact needs of the business. 
 Reuse of Free Software 
 Every effort has been made to reuse existing code and projects where feasible. 
 Versioning System 
Due to the modular nature of GNU Enterprise care must be taken to ensure that packages are compatible with one another. To ensure this level of compatibility every package and object must register it version level upon installation. This allows other packages and objects to specify which items, and versions of those items, that they are dependent upon. 
 Best Practices 
Because GNUe will be in use in a wide variety of industrys and will have influence from many developers as well as many users best practices will be developed. This allows companies new to the digital age or just forming to see how some well established companies are using technology and to build off their successes if they wish. In the future we see possibility of GNUe user groups as well as GNUe conferences and/or GNUe team showing presence at open source conferences. 
 Internationalization 
GNUe already has representation on development team from Austria, Spain, Belgium, Norway, Finland, Estonia, United States and others. Which guarantees strong support for both foreign currencies, multi-languages (docs and applications) as well as 24/7 developer end user support and close proximity for conference / user group attendance. Something not even large scale ERP products are doing well. 
Examples
The best way to understand what GNU Enterprise does is through examples.
High Level Demo
We'll start with a very high level demo which involves the sale of an item from inventory. The sale of this item has caused the inventory levels to drop below the reorder point (in this example there are no parts kept in stock so reorder point is zero) 
 The entry of the sale into GNU Enterprise would cause the inventory system to review the part. 
 The inventory levels are too low so either a purchase order could be automatically generated or the purchasing department could be notified with a request for purchase. 
 Once the order is placed with the vendor the system tracks these tentative parts so that additional sales can be processed with approximated ship dates. 
 When the parts arrive, their entry into the system alerts the shipping department with a list of orders that can now successfully be shipped. Accounting is notified that the order has been received and vendor payment is acceptable. The delivery efficiency of the vendor is tracked based upon the vendors promised delivery date vs the actual date of product arrival. 
 The shipment of the parts cause an invoice to be generated of the accounting department that the customer should invoiced. 
 Payment from the customer closes the order. 
Consultants
Consultants can use GNU Enterprise to reduce the time they spend maintaining custom solutions for their customer. In addition they can greatly increase the speed in which they can respond to customer requests. 
As an example we'll look at the steps Carl D. Consultant takes to install and customize GNU Enterprise to meet the needs of his customers. 
We'll first start at the local car dealership where Carl 
•	 Installs GNU Enterprise - Core 
•	 Installs the Car Dealer template(s)/package(s) which were created by some other car dealership. And, in the spirit of sharing uploaded to the GNU Enterprise package(s)/template(s) library. The template(s)/package(s) specifically.... 
•	 Modifies the CRM module included in the GNU Enterprise install to include a field to track a customers favorite type of car. 
•	 Installs the needed components, modules, and packages to provide an auto maintenance history system to the repair shop. 
•	 Tweaks the generic inventory module to handle issues specific to automobiles 
•	 Installs the needed components, modules, and packages to maintain an auto parts counter 
•	 Installs his custom birthday tracking component. The component specifically.... 
•	 Modifies the CRM module included a field to track a customers date of birth. 
•	 Installs a component that generates a report of customer's upcoming birthdays. This allows the dealer to send birthday greetings to his prior customers. 
•	 Installs module(s) to add specific modifications to the system the car dealer requested. 
 At the local doctors office 
•	 Installs GNU Enterprise - Core 
•	 Installs the Medical Facility template(s)/package(s) which he created and maintains for this customer. He has also made these template(s)/package(s) available to others via the GNU Enterprise web site. The template(s)/package(s) specifically... 
•	 Adds features needed for insurance tracking 
•	 Adds patient medical records tracking 
•	 Install pharmacy template, found on GNU Enterprise web site, to maintain the local office's pharmacy. This template specifically.... 
•	 Tweaks inventory module to handle drug expiration 
•	 Modifies CRM module to check current medical & check for drug interactions 
•	 Altered his generic medical facility package to include features this customer did not want shared with other users of GNU Enterprise. Features they felt gave them a competitive advantage. 
•	 Installs his custom birthday tracking component 
•	 Installs module(s) to add specific modifications to the system the car dealer requested. These modules specifically.... 
 At the local school 
•	 Installs GNU Enterprise - Core 
•	 Installs Maintenance template(s)/package(s), which was donated to GNU Enterprise, These template(s)/package(s) specifically.... 
•	 Tracks building maintenance 
•	 Provides a preventative maintenance system 
•	 Installs Education template created by the staff at O.P.U (Our Public University) and donated to GNU Enterprise. The template specifically.... 
•	 Tweaks inventory module to deal the students not parts 
•	 Adds sports event tracking module 
•	 Installs customizations he developed for the school to handle the schools odd dining system 
All the modules above come with modification files for screens, new screen definitions, triggers, fields, objects, functions, etc. He verifies the systems, their screens, completes testing, trains the staff, and gets paid. 
Now we release the new improved basic distribution (Now with 50% more bytes in every tarball!) 
He simply does something like 
rpm -U generic-1.6.8.rpm 
at all sites 
He runs a few tests, charges the customer the upgrade fee. Or, because he's in and out so quickly his yearly maintenance fees are inexpensive so his customers don't mind subscribing to them. 
He's not burning any time merging GNU Enterprise updates into sections of code he had to alter for each business. He's not hand merging his screen changes into the system. 
Kathy then releases a new Maintenance template that adds a feature the school has been talking about but would cost more than they care to spend on Carl to create. Carl says, "Tell you what, since you're such a good customer. And I'm such a great guy. We'll get it done for only $$ instead of $$$$". He does a 
rpm -U maintenance-2.0.1 
tests, trains. Schools happy because they got their feature. Carl's happy because he's made a little money where he would have made none. 
Templates/Packages
It would be almost impossible for a small group of developers to oversee every aspect of GNU Enterprise. In order to deal with this complexity the project is decomposed into separate projects known as packages each with vertical industry templates. Each package consists of everything needed to provide a single feature set to GNU Enterprise. Templates are a way to group the packages by industry. For example, the GNUE Accounting package provides General Ledger, Accounts Payable, Accounts Recievable, etc. capabilities to the system. (More diagrams and explanations coming soon.) 
Categories
 
Standard
For a package/template to be considered standard it must be developed within a specific set of guidelines. These guidelines ensure that the package will work on any system that has successfully installed the basic distribution. They also ensure that the package is friendly toward other GNU Enterprise packages. 
The basic distribution of GNU Enterprise will contain several packages that are determined to be essential to a majority of businesses. Only standard packages will be considered for inclusion in the basic distribution. 
Extended
Extended packages are packages that have requirements beyond those of the standard package. They might require an administrator to install additional languages on the system. They must however meet compatibility requirements. Extended packages are considered safe to use they simply require additional effort during setup of the system. 
Unfriendly
Unfriendly packages are the "hacks" that almost everyone has utilized at one time or another. They bypass all guidelines so they can "just get the job done". Updates to the system may cause these packages to break themselves, or the system. 
Base Packages
Table 1-1. Base Packages
 GNUe Core 	The general GNU Enterprise Tools. GNUe Forms, GNUe Reports, GEDI, GEAS and EWOK. 	
 Accounting 	Accounts recievable, Accounts Payable, General Ledger, etc. 	
 Budget Management 	Forecasting, Analysis, Controls, Auditing, etc. 	
 Customer Relationship Management 	Sales Management, Help Desk, etc. 	
 E-commerce 	E Shopping, E Merchandising, E Order Processing, etc. 	
 Human Resources 	Payroll, Time and Attendance, Benefits Management, etc. 	
 Project Management 	Resource Allocation, Cost Estimation, etc. 	
 Research and Development 	Bug Tracking, Statistics, etc. 	
 Supply Chain 	Inventory, purchase orders, etc. 	
 Point of Sale 	Point of Sale, Scanning, etc. 	

 The rest are to be determined. 
Other Packages
None available yet.
Architecture
Most GNU Enterprise programs are broken down along a N-Tier architecture. Which consists of 
Back-end
GNU Enterprise relies on a third party SQL based RDBMS for data storage. GEDI will allow support for a variety of database systems. (GEDI Proposal and information coming soon.) 
Initial development efforts center around the usage of the PostgreSQL RDBMS or unixODBC. 
Business Objects
Business objects are the heart of the GNU Enterprise system. These CORBA enabled objects provide most of the business logic in the system. 
Application
Applications can be broken down into two types, those that provide a user interface and those that do not. 
For applications that provide a UI this would be the logic behind the interface. It doesn't contain any business logic in most cases, that's one layer down. It contains the processes that occur when a trigger is fired from the ICL (button X is pressed, app has requested shutdown, menu item Y selected, etc.) 
If all ICLs support a standard set of form widgets, and a standard set of functions like get_functions required to provide a list of defined functions in the application. It seems possible to develop a nice IDE for simple apps along the lines of VB. 
An application could also be written at this level that would "simulate" the old SQL*Forms program (with all it's flaws and bonuses). It would bypass the lower levels and would make a nice GUI builder for direct table access (something we should probably avoid, but someone, somewhere will need it) 
Most developers new to GNUe would work in at this level using only the higher level business objects and the IDE. 
The other type of applications would be applications that perform basic batch style processing on the GNUe objects. 
ICL
Interface Client Level (aka Thin Client) 
These programs are basically identical regardless of what language/platform they cover. They assume a certain number of procedures are available from applications. One of the most important would be a "get_ui" call that would tell the application to send a description of the form to be drawn (encoded in XML). These programs would handle mapping UI widgets we've defined as valid for an OBE user interface. Things like entries, labels, lists, picture, text, notebook tabs, triggers, etc. 
Tools
GNU Enterprise will provide several tools that provide a powerful application development framework. 
GNUe Forms
 GnuE Forms actually consists of two separate programs. A designer which generates user interface definition files and a client which displays screens and accepts input from the user. 
The GnuE Forms painter provides developers with a system that allows rapid development of data entry screens. A developer simply chooses the objects and fields of interest and arranges the interface widgets to their liking. The system then generates a XML based interface definition file that is used by the clients. 
The GNUe Forms client reads the interface definition file produced by the designer and generates a data entry screen based upon its contents. 
Since the interface definition file is simple XML text it is very portable. Clients can be written for any number of display and data entry technologies and all utilize the same interface definition file. Thus building a single screen via the desinger instantly makes it available to all clients. 
In addition programs can be written to communicate directly with a client using its XML interface definition language. This allows programmers to bypass limitations of the screen designer while retaining the robust, standardized front end clients. 
GNUe Reports
GNUe Reports shares many features with GNUe Forms. It is comprised of a report designer and a client that generates the requested output. Report definition files are also XML based. And programs can communicate directly with the XML reports definition language much like they can with GNUe Forms. 
GEDI (GNU Enterprise Data Interface)
Data abstraction layer. Allows single API to all data sources. So the client has one set of calls it uses, but can access different vendors databases or even CVS or XML files. Similar to Borland's Database Engine or other data abstraction tiers. It will encompass much more than that and a proposal is forth coming. 
EWOK (Enterprise Wide Office Kommunication
Integration for faxing, telephony and other such communcations with in GNUe. 
GEAS (GNU Enterprise Administration System)
Security administration and over GNUe administration functionality. More to come with proposal. 

Appendix A. GNU General Public License 
                    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
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your programs, too.

  When we speak of free software, we are referring to freedom, not
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this service if you wish), that you receive source code or can get it
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in new free programs; and that you know you can do these things.

  To protect your rights, we need to make restrictions that forbid
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These restrictions translate to certain responsibilities for you if you
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  For example, if you distribute copies of such a program, whether
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REPAIR OR CORRECTION.

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

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

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

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

    -one line to give the program's name and a brief idea of what it does.-
    Copyright (C) 19yy  -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 `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

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

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

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

  -signature of Ty Coon-, 1 April 1989
  Ty Coon, President of Vice

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

Appendix B. GNU Free Documentation 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 "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.
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 "Acknowledgements",
and any sections entitled "Dedications".  You must delete all sections
entitled "Endorsements."

6. COLLECTIONS OF DOCUMENTS

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

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

7. AGGREGATION WITH INDEPENDENT WORKS

A compilation of the Document or its derivatives with other separate
and independent documents or works, in or on a volume of a storage or
distribution medium, 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.