In this paper, we present JSIM, a Java-based simulation and animation environment being developed at the University of Georgia. The JSIM library includes many Java classes to make developing simulation models easy. A model is constructed by building a graph with nodes (e.g. Queues and ServerBays) and edges (e.g. Transports). A model of moderate complexity can be constructed with minimal effort. Furthermore, in a future release of JSIM, much of the code will be created by a graphical designer. Using the built-in features of JSIM, the design diagram may be animated when the simulation is run. A novel aspect of the environment is that it follows the principles of Query Driven Simulation for the purpose of storing and retrieving simulation models and results in databases.