Jadex is a BDI reasoning engine, which means that it aims at simplifying the task of writing autonomous and intelligent software agents. The term reasoning engine stems from the fact that Jadex is conceptually independent of the underlying system infrastructure (since version 0.94) that is responsible for services like message passing. Currently, we provide Jadex for three different infrastructures: JADE, Standalone and DIET(experimental). One main advantage of this separation between agent behaviour and infrastructure is that Jadex agents can be defined in an abstract way independent of the underlying infrastructure making them usable in very different environments. Such environments may range from typical agent infrastructures such as JADE to component-oriented environments such as J2EE.