RSS

RSS Parser

Python Parser

Feed Parser
http://feedparser.org/
This is a "universal" feed parser, suitable for reading syndicated feeds as produced by weblogs, news sites, wikis, and many other types of sites. It handles Atom feeds, CDF, and the nine different versions of RSS.

Java parser

ROME (Rss and atOM utilitiEs)
https://rome.dev.java.net/
ROME is a set of Atom/RSS Java utilities that make it easy to work in Java with most syndication formats. It includes a set of parsers and generators for the various flavors of feeds, as well as converters to convert from one format to another. The parsers can give you back Java objects that are either specific for the format you want to work with, or a generic normalized SyndFeed object that lets you work on with the data without bothering about the underlying syndication type.

Informa
http://informa.sourceforge.net/
With Informa we enable you with a harmonised view on a news channel object model. Both channels and news items do have metadata assigned, it does not make any difference from which channel format they were originally retrieved (RSS 0.9x, RSS 1.0 / RDF, RSS 2.0, Atom 0.3).

Jakarta FeedParser
http://jakarta.apache.org/commons/sandbox/feedparser/