soulhuntre - "Current Linux 2.5 for instance..."

Red Hat's up to 7.X now...

soulhuntre - "Leaving a machine, ANY machine that is critical, up for years these days means that you are ignoring serious and important upgrades fixing bugs and security holes."

At one position, we had a solaris machine that had been up over two years. It was acting an an RLOGIN/DNS/TFTP server. There's no point in upgrading a machine that's doing it's job.

soulhuntre - "the migration to Unix variants is being seriously altered by the massive success of WindowsXP. It is fast, secure and stable. It is easy to administer..."

Agree, Windows XP (and 2K for that matter) are dramatic improvements over previous versions of windows, but I personally still would not load them on a critical system. Would you feel more comfortable with air traffic controllers relying on a Solaris platform or a Windows XP platform?.

easy to administer is the key to choosing windows over unix. Windows administrators are easier to find and less expensive to pay than Unix administrators.