RSS and Atom feed fetching

Hi!

Which feed fetching library should I use? I need support for
feedburner:origLink, , multiple 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.