Ruby is my prefered language: is easy to learn, has a simple clean syntax. Much nicer than perl, much easier than C/C++, no need to compile... Only problem might be the somewhat large memory footprint.
The standard installation has everything you need to to xml and network stuff. (I've run a small webserver on my Iliad (Webrick), to have remote access to it)
The best free available resource is http://www.ruby-doc.org/docs/ProgrammingRuby/
A great tool for the Iliad.
PS: Thomas, why not Ryby 1.8.7? It compiles without problems. If I remember well, 1.8.5 had some issues in the xml parser (REXML)