Thanks for your help. A database would be overkill, because this is just for learning purposes. I tried to avoid server-side code, because I wanted to test the code outside on a remote server, but there I can't start a Java server script. For this reason, I decided to test it locally by using the ServerSocketChannel class, which supports multithreading. The client sends a message (name and score) to the server and the server attaches this data to a XML file. However, I am not sure if I should send simple messages or better use objects, that wrap username and score. I would prefer the 2nd option and use XMLEncoder to store those objects in a XML file. When the client requests the higscore list, the server sends the whole list or maybe ten of the best players. Does this sound coherent?