Processing of emission inventories for regional modeling requires very large data bases and often requires days or weeks of calendar time to prepare the data for specific cases (scenarios) and geographic coverages, and many hours of mainframe computer CPU time. In order to address these problems, an emission processing system is being modified to be an integral part of initial operating version (IOV) of the Models-3 System, the object-oriented distributed-computing and analysis framework for the Environmental Protection Agency's (EPA) next generation of air quality models. The emission processor will use the most recent software and hardware computing techniques, including visualization, to provide user-specified gridded emission data to the chemistry and transport model (CTM) portion of Models-3 and allow analysis of the effects of different emission scenarios, including projections.