Because Jack was embeddable into other software systems, it was easy to control its movements through real-time commands. The emergence of large-scale military simulations led to incorporating multiple Jack instances as dismounted soldiers into distributed interactive simulations and virtual environments. When the Navy started using Jack in training systems, they opted to improve its shape, clothing, and motions by contracting with Boston Dynamics. That led to their development of DI-Guy and took us out of the mainstream military simulation business.