JavaSIM has been available since 1997 and is an object-oriented simulation package based upon C++SIM. It provides discrete event process-based simulation similar to SIMULA's simulation class and libraries. A complete list of the facilities provided follows:

• the core of the system gives SIMULA-like simulation routines, random number generators, queueing algorithms, and thread package interfaces.
• entity and set manipulation facilities similar to SIMSET.
• classes allow "non-causal" events, such as interrupts, to be handled.
• various statistical gathering routines, such as histogram and variance classes.
• debugging classes.

The system also comes with complete examples and test routines which illustrate many of the issues raised in using the simulation package. It is used by many commercial and academic organisations.