I-Cluster is an HP Lab oratories Grenoble initiative in collaboration with the ID-IMAG laboratory of INRIA Rh\364ne-Alpes. The aim of this research programme is to develop a production environment for idle computing power over an intranet. To be more precise, I-Cluster enables automatic real-time analysis of the availability, configuration and workload of machines on an intranet. When instantiation of a supercomputing function is carried out by a user, I-Cluster determines the most appropriate cluster for carrying out this function, allocates the machines and then begins distributed computing. To obtain this result, I-Cluster possesses a "sandbox" on each workstation on the intranet, enabling it to use the computing resources of these machines during idle periods. This document presents the sandbox developed for I-Cluster and its features.