Too many Ruby Atom libraries

Ruby now has 3 Atom Publishing Protocol libraries: atom-tools, atomutil and ratom. They all use the Atom namespace, and they're all incompatible. Not a great situation.

ratom uses libxml-ruby rather than REXML. It's embarassingly faster than atom-tools. ratom can parse the 1100 Atom Entries in my Venus cache in 0.25s; atom-tools takes 6s.

I haven't been able to get atomutil to work. I expect it is faster than atom-tools, too (though not nearly so dramatically); atom-tools parses an XML tree into a tree of Ruby objects (instead of just wrapping the XML tree). This may have been a mistake.