[nickpsecurity]

Genua on milcron's list is probably most significant. They are a defense contractor that sells firewalls, VPN's, data diodes, etc for business and government (including military). You can bet significant applications are protected with them.

This is the kind of role most of its users put it in. Others just use it like any other server OS with better reputation for reliability and security. Less patching... a time-consuming activity... at the least. Last one was similar reason for adoption of Argus Pitbull and SELinux w/ Tresys tools in their niches. Less worries when malware is going viral on the Internet and in media. ;)