The feasibility of using XLISP as extension language interpreter for typical modern Technology CAD tasks, involving several process simulation steps and a subsequent device simulation to extract device parameters for design optimization has been demonstrated in [31], [87], and [88]. Typical process and device simulation tasks are computationally expensive. Due to the portable implementation of the whole TCAD system, the task level shell is able to distribute the computationally intensive tasks even in heterogeneous computing environments. For this reason, the (system ...) call of XLISP had to be re-implemented using the base system libraries to allow operating system independent application process control.