Consider the need to simulate a set of entitities in an accurate way. All entities exist in an artificial timeline. Within 'steps' of this timeline, all entities can do certain operations. It is imperative that timed events, are handled accurately, and not in processing order. So simple threading isn't a proper simulation, nor is procedurally walking across all entities.

Processing may be slow, accuracy is key here.

I have some ideas how to implement this myself, but most likely something like this has been done before.

Are there any frameworks available for these purposes? Is there any particular paradigm more suitable?