% This is a mail-merge in PHP and latex.
\documentclass[10pt,a4paper]{letter}
\usepackage{graphicx}
\usepackage[latin1]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{txfonts}
\usepackage[british]{babel}

% To create sheets for the peel-off labels use this command.
\makelabels

%
% Your address
%
\address{Google Kreme\\Somewhere on the Internet\\Earth}

%
% Your signature
%
\signature{Kreme}

\begin{document}
	\selectlanguage{british}
<?php 
	/* Use php to collect the addressees and write the letters out to a tex file (std out). */
	
	/* The data-base (a flat-text file. The use of mysql is left as an exercise for the reader */
	$filename = "address.txt" ;
	$fd = fopen( $filename, "r") or die ("Can't open file $filename");
	
	while( !feof($fd) ) # Loop over all lines in the data-base file.
	{
		$line = fgets($fd, 8192);
		# line is not empty and line does not start with '#', it must contain something...
		if ((strcmp($line,"") != 0) && (strcmp($line[0],"#") != 0)) 
		{
			$elements = explode( "!", ereg_replace("\n", "", $line) );
?>
%:<?php print "$elements[1]\n"; ?>
	% A letter is contained in a \begin{letter} ... \end{letter} environment 
	% The argument to the letter environment contains the address
	% where the letter is supposed to arrive in a few days.
	%
	\begin{letter}{<?php print "$elements[0]"; ?>}
		%
		% Opening-line: Hello World!
		%
		\opening{<?php print "$elements[1]"; ?>,}
		%
		% The actual letter (there is an enlish translation below, dutch needs more fields).
		%
		I hereby invite you to attend the defence of my thesis with the title ``The
		atmosphere in the laboratory: Measurements on scattering and absorption''.
		The ceremony will be on tuesday November 23\textsuperscript{rd}, 2004, and
		start at 15:45 in the aula of the Vrije Universiteit.
	
		The aula is located in the main building of the university, ``De Boelelaan'',
		number 1105 in Amsterdam. Parking in near the university is possible, but
		expensive. The building is easy to reach by public transport, travel
		directions are included.
	
		After the defence a party is planned to take place in Café ``de Sluyswacht'',
		Jodenbreestraat~1 in Amsterdam, you are cordially invited to join the party
		from 19:00 onwards, we will take care of the food. Directions on how to reach
		the party from the Vrije Universiteit are included as well.
		
		For further questions, you can contact me or my assistants xxxxxxxxxx xxxxxxxxxxx
		and xxxxxxxxx xxxxxxxxxx. In order to ensure enough food for all, we would like 
		to know about your attendance at least one week in advance.
		
		\closing{Kind regards,}
		\encl{Any anclosures}
	\end{letter}
<?php
		}
	}
	fclose($fd);
?>

% Do not forget to close the latex document
\end{document}

<?php
/*
  # The complete command-line:
  php uitnodiging-merge.php > uitnodiging-merge.tex \
      && pdflatex uitnodiging-merge.tex \
      && open uitnodiging-merge.pdf 
*/
?>