usually the best way to find out this sort of information is through 'google.com' typing in 'rdf dmoz' (w/o ''s) came up with :
http://www.dmoz.org/rdf.html
which you'll find links to :
http://www.dmoz.org and
http://www.w3.org/RDF/
which explains it. but basically, dmoz is a yahoo like directory created by unpaid volunteers and RDF is a way/format they present their data. rdf presents data in a compact/structured way so people like us can play with that data. sites like google, hotbot and many others use dmoz information as their directorys. they download the latest dmoz rdf and implement it as their directory. it is not limited to dmoz, it is a global standard that many use and implement. you could create an rdf and allow others to display the information too.
btw, with google you can choose to search only sites through your native tongue. see :
http://www.google.com/preferences.html
hope that helps!