Starting with NetLogo version 5.1.0, the use of the applets is unfortunately deprecated, as explained here.
So nothing working on line, but it is possible to download the introduction to the ABM - Le famiglie e le decisioni d'investimento simulation work and its .nlogo file and the related .zip file, containing data files to be placed in the same folder of the nlogo file (to download, in both cases it is better to right click).