Oldest open-source software kept by Army

As its name suggests, BRL-CAD — a computer-aided design system — was developed before ARL existed. It has been used for nearly three decades in support of modeling, simulation and engineering analyses of military assets and their environments including the design and analysis of vehicles, mechanical parts and architecture.

Dr. Paul Tanenbaum, director of the Survivability/Lethality Analysis Directorate, used BRL-CAD early in his career when he was an analyst at the bench and then later when he served on the team developing and maintaining it.