JR Tashjian

This plugin was created to retrieve and cache an RSS feed for use in a template.
What you do is pass the url to the feed you would like returned and the number of minutes you would like the feed cached for. The 
plugin will cache the RSS xml and return the feed as an object which you can loop through and output however you please.
New As Of Version 1.5: 
– Fixed a typo that caused the feed to be retrieved and cached every time. Credit: Binny V A (http://www.bin-co.com/blog/) – Thanks man!
<h3>General Usage</h3>
fetch_feed_cache() is the only function you will be using with this plugin. fetch_feed_cache() accepts 2 parameters.
<ol>
<li>(string) $url – This is the URL to the feed you would like to parse</li>
<li>(int) $cache_min – This is the amount of time in minutes you would like the feed cached for.</li>
</ol>
Here is an example of the plugin being used in a template:
<pre><code><?php $xml = fetch_feed_cache("http://jrtashjian.com/feed/", 60); ?>
<h3><?=$xml->channel->title?></h3>
<ul>
 <?php if( ! empty($xml)) : ?>
 <?php foreach($xml->channel->item as $item) : ?>
 <li><a href="<?=$item->link?>"><?=$item->title?></a></li>
 <?php endforeach; ?>
 <?php else : ?>
 Delicious doesn't seem to be working at the moment...
 <?php endif; ?>
</ul>
</code></pre>
Remeber, every feed could be different. If you need to see the structure of the object returned just use print_r(). 
Example: <code><?php print_r(fetch_feed_cache("http://jrtashjian.com/feed/", 25)); ?></code>

Fetch Feed

Fetches an RSS feed and returns RSS as array

David Shanske

Daniel Jalkut (Red Sweater)

mantonr

Adds a JSON Feed to your WordPress site by adding <code>/feed/json</code> to any URL.
The JSON Feed format is a pragmatic syndication format, like RSS and Atom, but with one big difference: it’s JSON instead of XML. Learn more at <a href="http://jsonfeed.org/" rel="nofollow ugc">jsonfeed.org</a>.

JSON Feed (jsonfeed.org)

This plugin is simple to install, adds no weight to your site, and does what it says on the tin.

Fetch Feed vs JSON Feed (jsonfeed.org)