Years ago I wrote a simple desktop app that put snow on the desktop. At the time it was written in Javafx script. The biggest problem I had at the time was that it would not stay on top. Instead I had to have it send itself to the top once a minute. This is because of the lack of facility to do this in the javafx script. Switching it to Javafx2, which has this facility, was a relatively straight forward affair. I was also able to add a settings screen that displays for 10 seconds before it starts to snow.
I did find that on my Linux mint install the snow was restricted to one screen and it did not go on to my other monitors. This is unlike my windows install which correctly retrieved the other monitor metrics and spanned the snowfall across to them. I can only assume that this is something to do with the Xorg display driver or the KDE desktop environment. This will require further investigation next time I decide to update the project.
The project was a nice smooth reintroduction to Java.
The project executable and source files can be found on the Sourceforge page here.