Evaluation of highscore implementation methods

Hello,
I want to implement a highscore list (simple XML file with players and their scores) without using a database or a server side scripting language like php. There are several possible ways to implement a remote highscore list:

  • Pure Java sockets
  • RMI
  • Apache Commons Net

However, I don’t know which one I should prefer. I have read, that RMI works well in local networks, but often doesn’t work very well over the internet. It would be nice if someone could briefly evaluate those options.