From what I've read, a screen saver is just a program that runs off specific commands from the prompt. I wanted to make one for a friend but I don't know what the commands are. Also, how can I make it so under the screensaver menu there are settings for the specific program?
C# probably makes the integration of the screensaver into Windows a lot easier. Firstly it is capable of producing Windows EXE file directly, and secondly the SetParent and subsequent calls in that tutorial might be hard to mimic in Java. Of course, there are some EXE wrappers for Java and the preview mode does not need to be implemented, so it is doable in Java.