User:Yershov
From Lazarus wiki
OpenSIMPLY
Project home page OpenSIMPLY is an open source free run-time library for discrete event simulation. The concept is suitable for the persons of a different programming and simulation experience.
Both style of simulation: blocks and the low level are available. Adopted Simula models can be used too. The simulation blocks can be relocated on run-time, so the model is flexible for real time modifications. There are global, selected and deferred statistics gathering modes.
Write model once: GUI and console output is implemented. Easy transfer of simulation data; remote simulation ready.
The project supplied with full documentation (HTML and CHM formats), insight help (pop-up hints) and tutorial.