This article presents an inter-application load balancing mechanism meant to improve the efficiency of execution for Java parallel and distributed applications in a network of workstations. One difficulty of such architectures is dealing with heterogeneity: workstations have different powers and operating systems. Moreover, the workstations are generally executing several processes, corresponding to an external load, outside the JVM, as in the case of multi-user systems. Consequently, heterogeneity and resource sharing are features included in the design of the dynamic load balancing in ADAJ. Two new Java tools, of calibration and of load measure, are proposed and used to extend the previously load balancing approach applicable on a dedicated and homogeneous environment.