Let's start by mentioning a few facts that can be very disconcerting to die-hard Linux and Unix fans. Serious computer viruses appeared first in Unix systems. And arguably the worst computer virus attack in history occurred on Unix systems about twenty years ago. The good news is that the lessons learned from this attack were integrated into the constantly evolving Unix and Linux systems. Of course, to some extent they have been integrated into protecting Windows systems, and that's also good news.

One of the reasons Linux surpasses Windows for virus resistance is that it, Linux, is open source. When an attack occurs hundreds if not thousands of techies start working on solutions and post them to the Internet. You won't have to wait for an anti-virus company to come up with something.

What other factors make Linux systems more virus resistant? For a virus to take effect it must be part of a running program. Simply opening an attachment in the Microsoft Windows environment does the trick. The last time (pun intended) I opened an electronic greeting card on my Windows computer I got a nasty virus and it took some time to remove it even with the aid of technical support. Linux systems won't launch the virus unless the user reads the email, saves the attachment, modifies the appropriate permission assigning execution permission to the attachment, and then explicitly executes the attachment. Unless all these steps are performed the virus just remains in quarantine. Of course an educated Linux user could carry out all these steps unleashing the virus but this unhappy state of events doesn't occur often in properly organized systems.

Another limits virus impact in the Linux world. Regular Linux users don't have permission to do a lot. Even if they unleashed a virus it wouldn't go very far. Getting beyond the individual computer requires administrative power - the kind held by Root Users in Linux and Administrators in Windows. Regular users of Linux are usually not accorded root permission. In contrast, on a newly installed Windows system the first user created is automatically an Administrator. We call that asking for trouble.

Just think - a regular Windows user has permission to install files that can run amok and destroy lots of good things. It seems that in Windows the operating system, the applications, and the data are inextricably intertwined. As if they were asking for trouble.

I have read that bananas are in danger. It seems that biodiversity is a thing of the past in banana-land or at least in the commercial banana world. So there is the possibility that one powerful banana virus can make banana splits a thing of the past. The very diversity of Linux systems offers some protection. And it's a LAMP onto the world as discussed in the next two articles.