Provably correct software (and memory and type safe languages!) are both important aspects. But they can still cause you to die in a software bug. The third and

Provably correct software (and memory and type safe languages!) are both important aspects. But they can still cause you to die in a software bug. The third and most important aspect is that the code must be viewable by any third party or individual. Open source here would be ideal, but at a bare minimum, we should be allowed to see the code that our lives depend on.