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 Simulazione ad agenti di un mercato di titoli con l'uso di algoritmi genetici simulation work and its .nlogo file and the .bsearch file for http://www.behaviorsearch.org (to download, it is better to right click in both cases).