RSS Feed from custom blog

<?php
require_once("includes/init.php");
// instantiate blog class
$blog = new Blog($db);
$posts = $blog->get_posts();
$lastpostdate = $blog->last_post_date();
header("Content-Type: application/xml; charset=UTF-8");
echo '<?xml version="1.0" encoding="UTF-8" ?>' .
    '<rss xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:sy="http://purl.org/rss/1.0/modules/syndication/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" version="2.0">'.
     '<channel>' .
        '<title>'.SITE_NAME.'</title>' .
        '<atom:link href="http://'.SITE_URL.'/feed/" rel="self" type="application/rss+xml"/>' .
        '<link>http://'.SITE_URL.'</link>' .
        '<description>'.SITE_NAME.'</description>' .
        '<lastBuildDate>'. date("D, d M Y H:i:s O", strtotime($lastpostdate['date'])) .'</lastBuildDate>' .
        '<sy:updatePeriod>hourly</sy:updatePeriod>' .
        '<sy:updateFrequency>1</sy:updateFrequency>' .
        '<language>en-GB</language>';

foreach ($posts as $post) {

     echo '<item>';
     echo '<title>'. $post['title'] .'</title>';
     echo '<link>http://'.SITE_URL.'/'. $post['slug'] .'</link>';
     echo '<pubDate>'.date("D, d M Y H:i:s O", strtotime($post['date'])).'</pubDate>';
     echo '</item>';
}

echo '</channel>'.
       '</rss>';

What is the init.php? Btw, it's cool and simple. Thanks.

init.php calls the config to pull the constants as well as running the autoloader for the blog class.

Thanks for your comments, for some reason I didn't get an alert about it.