An important space weather prediction tool is the ability to reconstruct the coronal magnetic field above solar active regions from observations of the vector magnetic field at the photosphere. A variety of numerical methods for computing the coronal field from the boundary data have been developed over the last ten years. The logical next step is evaluating the performance of the various existing numerical codes side by side on both synthetic and real data. This project will coordinate such an effort: test datasets will be produced and distributed to collaborators, tools for analyzing and comparing results developed, results of the analysis publicized, and a workshop organized for collaborators to discuss results of the comparison.
