JSim is a Java-based discrete event simulator of an M/M/s queue system. The target audience are students and educators who may use it to explain and understand the basic principles of the system.
JSim includes a library of classes that can be used to modify the application to simulate other types of queuing systems as well. Therefore, it may be used as starting point to build larger, application specific simulator.
The most recent update includes modification to almost all classes to include the option of creating a queue system of multiple queues and multiple servers to simulate M/M/s system.