Elodin is a simulation and testing platform from Elodin Systems that connects flight software to GPU-accelerated physics, so the same codebase runs against a virtual airframe and then against real hardware without rewiring the test harness. The core engine is open-source, built on Rust and Python with XLA and JAX under the hood, and runs locally — which matters when your IP can't leave the building. Swarm simulation scales to tens of thousands of actors on a single machine, per the vendor. Cloud-based Monte Carlo testing is a paid-only feature, so teams doing mission profile sweeps at scale will hit a pricing conversation before they hit a technical wall. The Aleph flight computer is a separate hardware product; teams evaluating only the simulation layer should scope the two independently.