As of today, the Postfix mail transport agent has almost 50,000 lines of code, comments not included.

Writing software that's safe even in the presence of bugs makes the challenge even more interesting.

When I write software, I know that it will fail, either due to my own mistake, or due to some other cause.

I don't expect an overnight change of all desktops to what the US Military used to call B3 level security. And even that would not stop users from shooting themselves into the foot.

Lack of documentation is becoming a problem for acceptance.

Windows favors multi-threading, which means that a service is implemented by one single process.

In a previous life I wrote the software that controlled my physics experiments. That software had to deal with all kinds of possible failures in equipment. That is probably where I learned to rely on multiple safety nets inside and around my systems.