twiggi web-based groupware Code

<?php
// +--------------------------------------------+
// | Twiggi web-based groupware.		|
// |						|
// | For copyright and license information 	|
// | please read the COPYRIGHT file.		|
// +--------------------------------------------+

class core
{
	static $instance = false;
	private $major_version = 2;
	private $minor_version = 0;
	private $state_version = "ALPHA";

	private function __construct()
	{
	}

	public function get_instance()
	{
		if (!core::$instance)
		{
			core::$instance = new core();
		}
		
		return core::$instance;
	}

	public function get_version()
	{
		return $this->major_version.".".$this->minor_version." (".$this->state_version.")";
	}

	public function show_page()
	{
		print "Twiggi web-based groupware core module is up and running. Version ";
	}
}

?>