In this distribution:

phptagengine.class.inc.php
  The PHP class definition of PHP Tag Engine, this contains the core code.

phptagengine.config.inc.php
  Put your config settings in here.

phptagengine.css
  Make things look pretty here.

phptagengine.inc.php
  Include this file in your project, in turn it includes the rest of the PHP Tag Engine files and handles AJAX requests.

phptagengine.php.js
  AJAX communication code.

languages/*
  Put your translations here.

yui/*
  Yahoo! Auto-Complete library code.

README.txt
  this file


See http://phptagengine.com/ for more information.