Parsing XML with REXML using Expat
Expat is the recognized big daddy of XML parsing. It's a stream-based XML parser written in C and, as a library, is used for XML parsing functions by many languages. Rubyists have tended towards REXML, however, a more flexible (though infinitely slower) parser. Sam Ruby, however, has come up with some techniques to get Ruby's REXML working with Expat.