Free simulation modeling software OpenSIMPLY

OpenSIMPLY update has been released. Version 2.2.1 supports 32-bit and 64-bit Windows and 32-bit and 64-bit Linux.

Graphical user interface and terminal are available for input and output in any operating system and platform.

Write your model once - simulate anywhere. Free download simulation software.

Critical memory manager makes modeling with OpenSIMPLY stable and controllable.


OpenSIMPLY is an open source modeling software based on discrete event simulation approach. The project is built as a free runtime library fully compatible with Delphi, Lazarus and Free Pascal.

Simulation with OpenSIMPLY is suitable for person of any experience. The project offers two styles of computer simulation modeling approach.

The first style is the block simulation where user connects the simulation blocks of different types and assignes required parameters. Simulation blocks are fully expandable in parameters and functionality.

The second approach is the advanced one and very similar to Simula programming language. User can create more faster simulation model of any complexity. Even the models in Simula with some adaptation can be used with OpenSIMPLY.

OpenSIMPLY is delivered as zip-package that contains besides sources the detailed documentation, insight help (pop-up hints) for Delphi and Lazarus IDE's, and the tutorial with executable examples for step-by-step learning.

Evaluate the examples of simulation models.

Watch the learning videos.

Areas of use

  • Science software Any characteristic of the system being researched with the model requires al least several simulation points. For acceptable confidence interval the number of entities in the simulation model has to be great enough for run-through especially for complicated systems. OpenSIMPLY runs fast, local or remote, with flexible formatted output for suitable forms and tables, as for GUI as well as for console mode ... learn more
  • Traffic simulation The project was originally developed for traffic analysis with clear and simple modeling ideology. Built-in functions of traffic theory help to check the traffic simulation results for some degenerate cases, that gives a good possibility for model verification ... learn more
  • Network simulation OpenSIMPLY performs network modeling for quite complicated cases. Built-in router rules and conditional diverting make it easy to create a model for typical architectures. Total route of the packet over the network can be traced and analized ... learn more
  • Education The use of OpenSIMPLY is quite useful for educational purposes. The clarity of Object Pascal helps beginners to make fewer mistakes due to programming language, but concentrate more on simulation approach learning. ... learn more


  • 11-Dec-2018

    Simply Memory Manager v.1.6 for Free Pascal and Lazarus has been released.

more news

Project features

  • Two styles of simulation. Even both styles can be used together. The simulation blocks can be used for the general description of system behavior, and the critical section can be written with advanced simulation technique. The simulation model can be written as in Delphi as well as in Lazarus and Free Pascal.
  • Deferred statistics gathering mode enables to take into account the steady state of the model. Certainly, the global and the selected statistics gathering modes are presented in the project too.
  • Dynamic model. OpenSIMPLY gives full flexibility of the model behavior description. The blocks are allowed to relocate during the simulation. That means that the model can change its configuration on runtime.
  • Remote simulation. Functionally OpenSIMPLY is remote simulation ready. Execution progress of the model running on remote computer can be checked with programmable interruption of the simulation process.

Licenses and special requirements

OpenSIMPLY is free computer simulation software. Learn more about the using.

For extra agreements as also for extra features not implemented in the project (blocks, rules etc.) please write a message in the section Feedback with the selected subject "special requirements". The reasonable conditions will be offered.

Further development of the project

  • Visual model designer (is underway)
  • Statistics report generator: Done.
  • Support for 64-bit Windows: Done.
  • Support for 32-bit Linux: Done.
  • Support for 64-bit Linux: Done.