I know Linux has a firewall. I know about iptables.
I know Linux has fewer viruses targeting it than Windows does.
But I strongly believe that Linux users badly need the kind of automated anti-viral patch management service that Windows users now take for granted. The present approach, in my view, just won't scale. (That's the logo for Linux Security on the right. Good people. I hope they won't take what I'm about to say as critical of what they are doing.)
I understand there are companies in this space, like Central Command and Kaspersky. They target a limited subset of the Linux base with high quality, albeit expensive solutions. I know there are many Linux experts who say that, because Linux doesn't have ActiveX controls, viruses aren't a problem. I know that many Linux distros, like Gentoo, have their own security projects.
But antivirus is a service, not software. We can cooperate on the software. We can make money on the service.
How do we get there?
The best way to get there, I believe, is through an open source process, unifying what is happening in all major distributions, and with all major Linux applications, then delivering a common set of APIs that will allow services to be created which automatically update customer boxes when necessary.
Adamantix claims to offer some of this. But such efforts need support, and investment, so that Linux becomes secure for everyone, by default.
Until that happens, I believe, Windows will continue to dominate the market. By default.