The document summarizes a work group meeting on techniques and tools for model intercomparison studies. It discusses several past and ongoing intercomparison projects, including City-Delta, AEROCOM, GEMS, and ENSEMBLE. It proposes the development of an "Atmospheric Tracer Model Intercomparison Tools Initiative" to facilitate data sharing and analysis across different intercomparison projects through the use of common standards, tools, and databases. The initiative would focus on model documentation, quality control, comparison, benchmarking, and improvement.