I question it. In my opinion, OpenBSD is the most secure OS that is likely to be used on a home computer. As for the most secure OS devised for any commercial

I question it. In my opinion, OpenBSD is the most secure OS that is likely to be used on a home computer. As for the most secure OS devised for any commercially available computing-capable device, I'd probably pick VxWorks. But for an RMS-level of paranoia, I might have to go with RTEMS on a FPGA acting as a J-Core (SuperH-2) CPU.