The Multimedia Integrated Modeling System (MIMS) Spatial Allocator is a free tool for generating spatial surrogates for emissions, changing the map projection of shapefiles, and performing other types of spatial allocation without requiring users to have a Geographic Information System (GIS). The tool outputs spatial surrogates for regularly spaced air quality model grids on one of several classes of map projections, including Universal Transverse Mercator (UTM), Lambert Conformal, and Latitude-Longitude. It supports a variety of standard and user-specified ellipsoids to approximate the shape of the earth. In addition to creating emission surrogates, other types of spatial computations can be performed by the tool, such as copying shapefiles to new map projections and aggregation. For example, county polygons and their attributes can be aggregated into state polygons with corresponding attributes. The tool can run on Unix or Windows computers, and scripts are provided to assist with running the tool on both Unix and Windows. This new tool bridges the gap between emission modelers and GIS analysts by providing a zero cost, easy-to-use, powerful, and portable system for spatial surrogate generation, changing the map projection of shapefiles, and other spatial analyses.