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>';

This code creates an RSS feed from a custom blog.

$blog->get_posts() returns the results of "SELECT * FROM blog_posts"

$blog->last_post_date returns the result of 'SELECT * from blog_posts ORDER BY id DESC LIMIT 1'

The resultant RSS feed validates as a valid RSS 2.0 feed.

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.