root/tags/2.1/wp-atom.php

<?php

if (empty($wp)) {
    require_once('wp-config.php');
    wp('feed=atom');
}

header('Content-type: application/atom+xml; charset=' . get_option('blog_charset'), true);
$more = 1;

?>
<?php echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>'; ?>
<feed version="0.3"
    xmlns="http://purl.org/atom/ns#"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xml:lang="<?php echo get_option('rss_language'); ?>"
    <?php do_action('atom_ns'); ?>
>
    <title><?php bloginfo_rss('name') ?></title>
    <link rel="alternate" type="text/html" href="<?php bloginfo_rss('home') ?>" />
    <tagline><?php bloginfo_rss("description") ?></tagline>
    <modified><?php echo mysql2date('Y-m-d\TH:i:s\Z', get_lastpostmodified('GMT'), false); ?></modified>
    <copyright>Copyright <?php echo mysql2date('Y', get_lastpostdate('blog'), 0); ?></copyright>
    <generator url="http://wordpress.org/" version="<?php bloginfo_rss('version'); ?>">WordPress</generator>
    <?php do_action('atom_head'); ?>
    <?php while (have_posts()) : the_post(); ?>
    <entry>
        <author>
            <name><?php the_author() ?></name>
        </author>
        <title type="text/html" mode="escaped"><![CDATA[<?php the_title_rss() ?>]]></title>
        <link rel="alternate" type="text/html" href="<?php permalink_single_rss() ?>" />
        <id><?php the_guid(); ?></id>
        <modified><?php echo get_post_time('Y-m-d\TH:i:s\Z', true); ?></modified>
        <issued><?php echo get_post_time('Y-m-d\TH:i:s\Z', true); ?></issued>
        <?php the_category_rss('rdf') ?>
        <summary type="<?php bloginfo('html_type'); ?>" mode="escaped"><![CDATA[<?php the_excerpt_rss(); ?>]]></summary>
<?php if ( !get_option('rss_use_excerpt') ) : ?>
        <content type="<?php bloginfo('html_type'); ?>" mode="escaped" xml:base="<?php permalink_single_rss() ?>"><![CDATA[<?php the_content('', 0, '') ?>]]></content>
<?php endif; ?>
<?php rss_enclosure(); ?>
<?php do_action('atom_entry'); ?>
    </entry>
    <?php endwhile ; ?>
</feed>