RSS and Atom feed fetching

Hi!

Which feed fetching library should I use? I need support for <feedburner:origLink>, <enclosure>, multiple <comment> elements, all RSS dialects and so on...

The parser should return a data structure that is independent of the feed format, i.e. the same for RSS1, RSS2 and Atom, ...

Any plugins or libraries that you could recommend? Is there something like UFP for Ruby?

Ping.