One of the principal aims of the distributed programming research is the definition of paradigms which permit the description of Global Computation, as Cardelli calls them, i.e. computations on net of heterogeneous sites. In this context, it seems that the code mobility is a good paradigm for limiting network traffic. Here we will describe the implementation, in Ada95, of Klaim, a kernel language that gives the possibility of coordinating the activity of processes running on a net and uses code mobility.