




		Teaser and Firecat Protocol V 2.0 Draft 8
		=========================================

			Copyright (c) 1998 Matthew Parry
			<mettw@bowerbird.com.au>



1 Copyright
2 Introduction
  2.1 About TFP
  2.2 TFP 2.0
  2.3 Basics
  2.4 Design of TFP 2.0
3 TFP structure
  3.1 Negotiate TFP version to use
  3.2 Client authenticates itself.
  3.3 Request type of communication to establish
  3.4 Closing connection
4 Data transfer
  4.1 STATUS
  4.2 REQINFO
  4.3 NEWACC
  4.4 SETINFO
  4.5 SENDDATA
5 Default methods
  5.1 SENDFILE
  5.2 SENDURL
  5.3 IMESSG
  5.4 TALK 
  5.5 VOICE
  5.6 VIDEO
  5.7 SHARAPP 
6 TFP sub-protocols
  6.1 SENDURL
  6.2 IMESSG
7 Error IDs
8 Copyleft


1 Copyright
===========

    This protocol is free information; 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 protocol 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 protocol; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


2 Introduction
==============

2.1 About TFP
-------------

	The Teaser and Firecat System (TFS) consists of two programs:

		TEASER - The TFP server
		FIRECAT - The TFP client

	Teaser and Firecat is both a bookmarking system for network
	services and an online status of contacts system.  By
	"bookmarking system for network services" it is meant that
	a user/organisation can list all of their networking services
	under a single URL - Thier Teaser And Firecat Address (TFA).
	For example, a user can find the email address(es)/web site(s)/
	FTP site(s)/etc of one of their friends or an organisation 
	easilly through thier Firecat.  They only need to add the
	friend's/organisation's TFA to thier Firecat's list of
	bookmarks and every service associated with that TFA can
	be found automatically for them.

	A part of these "networking services" also includes the
	various types of communication that can be established
	between two or more people, such as video conferencing etc.
	With TFS your Firecat will automatically download a
	list of protocols that the person you want to contact can
	use and select the best possible protocol that you can 
	both use.  There will be a base set of `standard' prtocols
	to ensure that two Firecats will always be able to establish
	each type of communication, but the system can be expanded to
	include new technologies as they become available.

	The "online status of contacts" part of the system is
	basically the same as the ICQ idea.

2.2 TFP 2.0
-----------

	With the development of a Teaser and Firecats for TFP 1.x it
	has become clear that the original design of the protocol,
	although simple to implement, is too restrictive and inflexible
	for general use. The instant messaging system, for example, does 
	not work when a computer is behind a firewall.  Also, if the
	protocol is extended to include other features the structure
	of the protocol will take on a patchwork appearance.

	The purpose of this draft is to overcome these limitations.  The
	basic structure of the protocol will be designed to allow:

	* Enough flexibility to overcome different network setups - such
	as firewalls.

	* Allow the protocol to be seamlessly extended to include new
	technologies as they become available.


2.3 Basics
----------

	Each user will have a unique identifier at their local Teaser
	of the form

		tfp://user@host[:port]

	eg

		tfp://mettw@teaser.bluecow.com

	This will be used to identify each user on the TFS.  It is 
	referred to as the Teaser and Firecat Address (TFA).

	To change online status each Firecat will send a request to
	their Teaser to update their status.  

	To find the status of another TFS user the requesting user will 
	send a request to their Teaser (The requesting Teaser)
	about the queried user.  The requesting Teaser will then send a 
	request to the queried user's Teaser (The queried Teaser) which will 
	report on the online status of the queried user.  The requesting 
	Teaser then reports back to the requesting user.  The queried Teaser
	keeps a record of the fact that the requesting Teaser is
	interested in the queried user and will report any changes in
	online status to the requesting teaser until told not to by
	the requesting teaser.  The requesting teaser will keep a record
	of the fact that the queried Teaser will report on the status
	of the queried user and will tell the queried teaser to stop
	reporting when no more of the requesting teaser's users are 
	interested in the queried user.

	To explain...

 	Say we have three TFS users: tfp://mettw@teaser.bluecow.com; 
	tfp://annette@teaser.bluecow.com and tfp://static@teaser.dolphin.com

	ie

		TEASER			FIRECAT
		-------------------------------
		teaser.bluecow.com	mettw
					annette
		-------------------------------
		teaser.dolphin.com	static


	and user mettw comes online.  First mettw updates his online
	status:

		mettw   --------->   teaser.bluecow.com
			 online

		mettw   <--------    teaser.bluecow.com
			  OK

	mettw then wants to know the status of static.  First he sends
	a request to his local teaser:

		mettw   -------------------------->   teaser.bluecow.com
			tfp://static@teaser.dolphin.com?

	which forwards the request to static's teaser:

		teaser.bluecow.com ------------> teaser.dolphin.com
				      static?

	who then reports on the status:

		teaser.bluecow.com <--------- teaser.dolphin.com
				     offline

		mettw <--------- teaser.bluecow.com
			offline

	But when static comes online Dolphin knows that Bluecow is 
	interested, so it sends an update to Bluecow who then passes 
	it on to mettw.

		teaser.bluecow.com <--------------------- teaser.dolphin.com
					static is online

		mettw <--------------------------- teaser.bluecow.com
			tfp://static@teaser.dolphin.com
			is now online

	When annette comes online and requests the status of static
	Bluecow automatically tells her that he is online
	without going through Dolphin.

	Dolphin will now continue to send updates to
	Bluecow until it is told that Bluecow is 
	no longer interested in static.  Bluecow won't do 
	this until both mettw and annette go offline.


2.4 Design of TFP 2.0
---------------------

	The original design of TFP made strict and inflexible assumptions
	about how two Firecats will communicate.  No such assumptions
	will be made in TFP 2.0.  Whenever a Firecat wants to communicate
	with another the Firecat will contact the relevant Teaser and ask
	it how to conduct the data communication.  To prevent a particular
	Firecat gaining a monopoly by implementing complicated or system
	specific data transfer schemes each type of data transfer will
	have a simple default value that *must* be implemented by
	every Firecat.

	So, for example, if user tfp://static@teaser.dolphin.com wants to
	send an instant message to tfp://mettw@teaser.bluecow.com then 
	static's Firecat will first contact teaser.bluecow.com as follows:

	FIRECAT				      TEASER
	--------------------------------------------
	TFP 2.0
						TFP 2.0
	[The Teaser and Firecat negotiate a TFP version
	to use in the communication.]

	REQINFO tfp://mettw@teaser.bluecow.com.au
	[I want to get some information about the user
	tfp://mettw@teaser.bluecow.com]

						OK
	[I have that user, proceed]

	IMESSG
	[What methods can I use to send instant
	messages to mettw?]

						IMESSG imessg://mettw@teaser...
	[You can use the default method of sending a message to
	this teaser for forwarding to the user.]

						RMI <parameters>
	[Or, you can use the Java RMI method by using the
	parameters <parameters>.]

						DONE
	[There are no more ways to send an instant message
	to mettw].

	QUIT
	[Close the connection.]


	Static's Firecat will then decide whether it can use the
	RMI method or (based on user preferences) if it wants
	to use it.  If it doesn't know about the RMI method then
	it can fall back to the default method.  It is therefore
	assured that two Firecats will always be able to implement
	each form of data communication without restricting
	future innovation.


3 TFP structure
===============

	All TFP 2.0 communications will follow the structure outlined
	below:

	1) Negotiate TFP version to use.

	2) (Where applicable) Client authenticates itself.

	3) Request type of communication to establish.

	4) Data transfer

	5) Close connection or return to step 3.

3.1 Negotiate TFP version to use
--------------------------------

	The client is the Teaser/Firecat who establishes the
	connection and the server is the Teaser/Firecat who was
	listening on the port.

	CLIENT:	TFP <SP> (version A) <CRLF>
	SERVER: SORRY <SP> (error id), <SP> (error mesg) <CRLF>
		[or]
		TFP <SP> (version B) <CRLF>
	[version B must always be <= version A]
	[If version B < version A then:]
	CLIENT: TFP <SP> (version B) <CRLF>
	SERVER: TFP <SP> (version B) <CRLF>

3.2 Client authenticates itself
-------------------------------

	If the client is a Firecat:

	CLIENT: USER <SP> (TFA) <CRLF>
	CLIENT: PORT <SP> (port client is listening on) <CRLF>
	CLIENT: PASSWORD <SP> (password) <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>
		[connection is closed by server on authentication
		failure]

	If the client is a Teaser:

	CLIENT: DN <SP> (Teaser's Domain Name) <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>
		[connection is closed by server on authentication
		failure]


3.3 Request Type of communication to establish
----------------------------------------------

	The following commands may be sent by the client to
	the server:

	[Preceded by client authentication]
	STATUS <SP> (TFA) <CRLF>
	[The client wants to set/request the status of TFA]

	REQINFO <SP> (TFA) <CRLF>
	[A Firecat/Teaser wants to get some information about another
	user]

	NEWACC <SP> (TFA) <CRLF>
	[A Firecat wishes to establish an account at the Teaser]

	[Preceded by client authentication]
	SETINFO <CRLF>
	[Firecat wishes to change information about itself stored
	on the Teaser's database]

	SENDDATA <SP> (TFA) <CRLF>
	[Client wishes to send some information to TFA
	via the Server.  The type of data to send must be defined
	in section 4.5 (Data Transfer: SENDDATA).

	The server will then respond with:

	OK <CRLF>
	[Continue with the data transfer]
	[or]
	SORRY <SP> (error id), <SP> (error mesg) <CRLF>


3.4 Closing connection
----------------------

	CLIENT: QUIT <CRLF>
	[Connection is then closed by server]


4 Data transfer
===============

4.1 STATUS
----------

	The following commands may be sent by the client following
	a STATUS command:

	CLIENT: REQSTAT <CRLF>
	[Request the user's online status]
	SERVER: ONLINE|OFFLINE|BUSY|BACKINFIVE <CRLF>

	CLIENT: STPSTAT <CRLF>
	[Stop sending status updates about user]
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: SETSTAT <SP> ONLINE|OFFLINE|BUSY|BACKINFIVE <CRLF>
	[Set the user's online status]
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: GETPERS [<SP> (Field)] <CRLF>
	[Get some personal information about the user]
	SERVER: SORRY <SP> (error id), <SP> (error mesg) <CRLF>
	[or]
		(Field) <SP> (Value) <CRLF>
	[This command may be repeated if more than one field is
	present and (Field) was not given by the client]
	SERVER: DONE <CRLF>

	CLIENT: SETPERS [<SP> (Field)] <CRLF>
	[The client wants to set its personal info]
		(Field) <SP> (Value) <CRLF>
	[This command may be repeated if more than one field is
	to be set and (Field) was not given.  If (Field) is not given
	then any existing field that is not given a value in this
	connection is deleted from the database]
		DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error message) <CRLF>

	There is no restriction on what (Field) is, but the default
	fields are:

	DOB - Date of Birth
	CNAME - Christian Name
	SNAME - Surname
	MNAME - Middle Name(s)
	NICK - Online nickname
	PHONE - Phone number (Including national prefix)
	COUNTRY - Country of residence/office
	STATE - State of residence/office
	CITY - City of residence/office
	ADDR - Street and number of residence/office
	PCODE - Post/Zip code
	
	All dates sent to the Teaser should be in the form:
	
	YYYY/MM/DD[.HH:MM[:SS[.(fraction of secs)]] <SP> (Timezone)][ <SP>
	AD|BC] <CRLF>

	If AD|BC is ommitted the AD is assumed.  (Timezone) should be given
	as the number of hours ahead or behind GMT.

4.2 REQINFO
-----------

	The following commands may be sent by the client following
	a REQINFO command:

	CLIENT: URL <SP> (protocol) <CRLF>
	[Request the user's URL for (protocol), where (protocol)
	is any standard URL prefix - eg http, ftp, saft, and also
	tfp to see if the user has any other TFAs]
	SERVER: URL <SP> (URL) <CRLF>
		DESC <SP> (one line description) <CRLF>
	[The last two lines may be repeated if there is more than one
	URL of this type for the user]
	SERVER: DONE <CRLF>

	CLIENT: DYNURL <SP> (protocol) <CRLF>
	[Request the user's Dynamic IP URL for (protocol), where (protocol)
	is any standard URL prefix - eg http, ftp, saft.  This is to
	allow people easy access to the services on a dialup PC]
	SERVER: URL <SP> (URL) <CRLF>
		DESC <SP> (one line description) <CRLF>
	[The last two lines may be repeated if there is more than one
	URL of this type for the user]
	SERVER: DONE <CRLF>

	NB Email requests should be made with the commands

	CLIENT: URL <SP> smtp <CRLF>
	
	or

	CLIENT: DYNURL <SP> smtp <CRLF>

	The server will then reply with a URL of the form

	smtp://user@host

	This is to avoid the ugly quasi URL of `mailto:user@host' and 
	make email addresses conform to
	the URL style.


	The following commands are implimented to allow standard ways
	to communicate with the user.  Note that some of them (such
	as the default method for SENDFILE) can also be accessed
	via the URL command.

	CLIENT: SENDFILE <CRLF>
	[Request methods for sending any type of file to user]
	SERVER: (method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	SERVER: DONE <CRLF>


	CLIENT: SENDURL <CRLF>
	[Request methods for sending any type of URL to user]
	SERVER: (method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	SERVER: DONE <CRLF>

	CLIENT: IMESSG <CRLF>
	[Request methods for sending an instant message to user]
	SERVER: (method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	SERVER: DONE <CRLF>

	CLIENT: TALK <CRLF>
	[Request methods for establishing a talk session with user]
	SERVER: (method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	SERVER: DONE <CRLF>

	CLIENT: VOICE <CRLF>
	[Request methods for establishing a voice conference with user]
	SERVER: (method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	SERVER: DONE <CRLF>

	CLIENT: VIDEO <CRLF>
	[Request methods for establishing a video conference with user]
	SERVER: (method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	SERVER: DONE <CRLF>

	CLIENT: SHARAPP <SP> (application) <CRLF>
	[Request methods for establishing a shared application with user]
	SERVER: (method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	SERVER: DONE <CRLF>


4.3 NEWACC
----------

	One or more of the following commands may be sent after a NEWACC
	command.  If a particular communication type is not defined then
	the Teaser will always respond with error 301 to requests
	for the info.  The PASSWORD command *must* be sent before
	the connection is closed, failing to do so will result
	in the teaser not creating the account.  After creating an
	account the user's status will automatically be set to
	ONLINE by the server.

	CLIENT: PASSWORD <SP> (password) <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>
	
	CLIENT: URL <SP> (protocol) <CRLF>
		URL <SP> (URL) <CRLF>
		DESC <SP> (one line description) <CRLF>
	[The last two lines may be repeated if there is more than one
	URL for this type of protocol for the user]
		DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: DYNURL <SP> (protocol) <CRLF>
		URL <SP> (URL) <CRLF>
		DESC <SP> (one line description) <CRLF>
	[The last two lines may be repeated if there is more than one
	dynamic IP URL for this type of protocol for the user]
		DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: SENDFILE <CRLF>
		(method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	        DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: SENDURL <CRLF>
		(method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	        DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: IMESSG <CRLF>
		(method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	        DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: TALK <CRLF>
		(method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	        DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: VOICE <CRLF>
		(method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	        DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: VIDEO <CRLF>
		(method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	        DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

	CLIENT: SHARAPP <SP> (application) <CRLF>
		(method) <SP> (parameters) <CRLF>
	[This command may be repeated if more than one method
	is available.  The default method must *always* be sent]
	        DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>


	The following command sets what action to take when one
	of the TFP sub-protocols are sent to the teaser.  The 
	default actions given *must* be implemented by the teaser, 
	but new ones may be added.  Multiple actions may not
	be given.

	CLIENT: SENDDATA <SP> (TFP sub-protocol) <CRLF>
	[action to take if a (TFP sub-protocol) connection is made
	to the Teaser to send data to the user]
		FORWARD <SP> (URL) <CRLF>
	[where URL (usually) points to the firecat's own address]
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>


4.4 SETINFO
-----------

	After issuing a SETINFO command a client may send any of
	the commands defined in section 4.3 (Data transfer: NEWACC).
	The protocol does not allow for appending methods; every
	possible method must be sent with the new one.  ie, if
	the user has already defined the default instant messaging
	method but wants to add the Java RMI method, then the following
	communications will take place:

	CLIENT: IMESSG <CRLF>
		IMESSG <SP> (URL) <CRLF>
		RMI <SP> (parameters) <CRLF>
		DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY <SP> (error id), <SP> (error mesg) <CRLF>

4.5 SENDDATA
------------

	After issuing a SENDDATA command the client may use any
	of the TFP sub-protocols (section 6).


5 Default methods
=================

5.1 SENDFILE
------------

	The default method for sending files to a user is via SAFT 
	(Simple Asynchronous File Transfer).  The file can either
	be sent to the Teaser's host machine for downloading by the
	user via the O-SAFT (Offer Simple Asynchronous File Transfer) 
	protocol, or it can be sent directly to the user's computer.  
	Which of these will be used is set by the user.

	The syntax for the method is:

	SAFT <SP> (URL) <CRLF>

	Where URL is of the form

	saft://user@host[:post]


5.2 SENDURL
-----------

	The default method for sending a URL is via the TFP sub-protocol
	"SENDURL".

	The syntax for the method is:

	SENDURL <SP> (URL) <CRLF>

	Where URL is of the form

	sendurl://user@host[:port]

	(where the default port used is the teaser port)


5.3 IMESSG
----------

	The default method for sending an instant message is via the 
	TFP sub-protocol "IMESSG".

	The syntax for the method is:

	IMESSG <SP> (URL) <CRLF>

	Where URL is of the form

	imessg://user@host[:port]

	(where the default port used is the teaser port) 


5.4 TALK 
--------

	BSD talk??

5.5 VOICE
---------

5.6 VIDEO
---------

5.7 SHARAPP 
-----------


6 TFP sub-protocols
===================

6.1 SENDURL
-----------

	After negotiating a TFP version and setting the communication
	type to SENDDATA, the client and server share data:

	CLIENT: SENDURL <SP> (From TFA) <CRLF>
	CLIENT: URL <SP> (URL) <CRLF>
		BDESC <SP> (one line description of URL) <CRLF>
	[optional]
		VDESC
		(multi-line description of the TFA)
	[non-optional]
		<CRLF> DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY (error id), (error mesg) <CRLF>

	Which is then followed by either a QUIT or a new communication
	type.

	To prevent occurrences of the string `<CRLF> DONE <CRLF>' from
	interfering with the verbose description, if the client finds a line
	matching the regular expression:

	(<SP>)* DONE <CRLF>

	then it will add another space character to the start of the 
	line.  The server should then remove a space character from the
	start of any line that matches the regular expression:

	(<SP>)+ DONE <CRLF>




6.2 IMESSG
----------

	After negotiating a TFP version and setting the communication
	type to SENDDATA, the client and server share data:

	CLIENT: IMESSG <SP> (From TFA) <CRLF>
		(message)
		<CRLF> DONE <CRLF>
	SERVER: OK <CRLF>
	[or]
		SORRY (error id), (error mesg) <CRLF>

	Which is then followed by either a QUIT or a new communication
	type.

	To prevent occurrences of the string `<CRLF> DONE <CRLF>' from
	interfering with the protocol, if the client finds a line
	matching the regular expression:

	(<SP>)* DONE <CRLF>

	then it will add another space character to the start of the 
	line.  The server should then remove a space character from the
	start of any line that matches the regular expression:

	(<SP>)+ DONE <CRLF>


7 Error IDs
===========

	ERROR ID				MESSAGE
	-----------------------------------------------

	100					Not TFP
	101					Didn't follow declared TFP 
						version
	102					Unknown TFP version
	103					Unknown command

	200					Malformed TFA
	201					Unknown user
	202					You contacted the wrong teaser
	203					User is now at <TFA>

	300					Request not permitted
	301					Requested info not available
	302					You didn't set a password
	303					You didn't authenticate 
						yourself

	400					Couldn't contact Teaser
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8 Copyleft
==========

		    GNU GENERAL PUBLIC LICENSE
		       Version 2, June 1991

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

			    Preamble

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

			    NO WARRANTY

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

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

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

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

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

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