The Linux kernel has only been around since 1991, so that would make it seventeen years. And virii aren't the only things that can infest a box: worms, rootkits, back doors, and all sorts of other goodies can get in.
I have NEVER had a machine touched on my network behind a properly set up fire wall, but most importantly NEVER had a virus...
Now, that's not a function of Linux at all. That's a function of good security practice.
...and no, you can’t crack my machines.... and I doubt anyone can.
The GNU/Linux operating system and related open-source software applications are very good and significantly more secure than Windows, by default, because the operating system was designed with more of a focus on security than Windows. However, that doesn't mean it can't be broken, and thinking that it can't (or that your systems are impenetrable) is a very dangerous mindset.
Oh, and even if I could crack your boxen, I wouldn't, cause I have better things to do.
“The GNU/Linux operating system and related open-source software applications are very good and significantly more secure than Windows, by default, because the operating system was designed with more of a focus on security than Windows. However, that doesn’t mean it can’t be broken, and thinking that it can’t (or that your systems are impenetrable) is a very dangerous mindset.”
Like with Apple’s claims of better security (which it does have), it’s not foolproof and I make the assertion that if 90% of the world’s computers were running Linux or Apple, there would still be viruses.