Welcome

ROSS is an acronym for Rensselaer’s Optimistic Simulation System. It is a parallel discrete-event simulator that executes on multiprocessor systems and/or supercomputers. ROSS is geared for running large-scale simulation models (millions of object models).

This site contains documentation for both ROSS users (aka model developers) and ROSS developers. It also contains an overview and brief history.

If you are currently developing a ROSS model and would like to request a new feature, please create an Issue on Github.

Latest Updates

• Release 8.1.0

  announcement • Posted on Jul 23, 2025 • Elkin Cruz

  Our new release is packed with new features and bug fixes!! :D

• GVT Hook - Running custom code at GVT computation time

  feature • Posted on Jul 22, 2025 • Elkin Cruz

  Sometimes, we want to switch our model as it is running, or we want to pause the simulation and check what it is doing, or we want to checkpoint the whole thing. Well, that is finally possible with the GVT hook.

• Checking Reverse Handler - The debugging tool for PDES you didn't know you needed

  feature • Posted on Jul 22, 2025 • Elkin Cruz

  We have implemented a new synchronizaton algorithm: sequential rollback check (--synch=6).

• Args file: --args-file=options.txt

  feature • Posted on Jul 22, 2025 • Elkin Cruz

  ROSS new –args-file argument allows us to pass some arguments in a file.

• Release 8.0.0

  announcement • Posted on Jul 11, 2022 • Neil McGlohon

  This version includes all of the 2020-2022 work on Tiebreaking and various updates to develop since the last version.