feed-rss2.php
Displays your entries in RSS 2.0 format.
feed-rss.php
Displays your entries in RSS 0.92 format.
feed-rdf.php
Displays your entries in RDF/RSS 1.0 format
feed-atom.php
Displays your entries in Atom format.
feed-atom-comments.php
Displays comments – either the most recent comments on all posts, or the comments on a specific post – in Atom format.
feed-rss2-comments.php
Displays comments – either the most recent comments on all posts, or the comments on a specific post – in RSS 2.0 format.
http://example.com/category/categoryname/feed
http://example.com/tag/tagname/feed
http://example.com/author/authorname/feed/

1 <?php include_once(ABSPATH.WPINC.’/rss.php’);
2 wp_rss(‘http://feeds.feedburner.com/wprecipes’, 3); ?>
feed.informer.com
seems to only accept the most basic feed URL – requires account set up
feed2js.com
very flexible & will accept category defined feeds
feed.mikle/com/en
flexible & easy with reasonable sized source link
rssfeedconverter.com
not much control free with smaller source link
rssinclude.com
fairly customizable in the free version / includes some pre-packaged transitions / will accept category driven feed
www.fwnetwork.com/feed/free_rss_feed_to_html_converter.php
not many styling or selection options but clean w/smaller source link