The Generic Eclipse Modeling System (GEMS) is a MDD tool for Eclipse that allows for the rapid development of visual modeling tools for Eclipse based on EMF/GEF. Developers specify the rules for a domain language using a metamodel and the tool generates a diagram editor plugin that enforces the rules from the metamodel. Interpreters can then be written to traverse the model and generate code, perform analyses, or execute the model. The tool supports complex model analysis using Prolog; Java, OCL, and Prolog constraints, remote model updating via CORBA, applying CSS styles to models, model-to-model linking, exportable templates, and more.