1. A method of passing data among modules of a heterogeneous software system executing within at least one computer, the method comprising: classifying each call to a scripted function in the heterogeneous software system as either computationally expensive or computationally cheap; for each scripted function classified as computationally expensive, building a respective wrapper script with a call to the computationally expensive scripted function and no other calls to scripted functions; selecting two or more scripted functions to be executed within the heterogeneous software system in response to the two or more scripted functions being classified as computationally cheap; building a wrapper script by embedding, within the wrapper script, respective calls to the two or more scripted functions and XTable objects associated with the two or more scripted functions, respectively, and storing the wrapper script; executing the wrapper script thereby causing the two or more scripted functions to execute and use the respective XTable objects as input; wherein the two or more scripted functions are executed with one invocation of an interpreter of the two or more the scripted functions by the wrapper script; and storing results from execution of the two or more scripted functions, wherein the classifying, selecting, building, executing, and storing are performed and are executable by the at least one computer.