1. A computer program product comprising one or more physical computer-readable media having thereon computer-executable instructions comprising: one or more first runtime computer-executable instructions that are to be executed using a first runtime that operates using a first runtime environment; one or more second runtime computer-executable instructions that are executed using a second runtime that operates using a second runtime environment; and one or more environment sharing computer-executable instructions that are structured such at least a portion of the first and second runtime environments may be shared so as to be accessible by both runtimes.