JE_Kincaid asked on Extreme Tech whether or not Linux is immune to viruses.

I am wondering about Linux and viruses. I have an acquaintence who claims to be very knowledgable on Linux (I am not...at all), make the statement that "there are no Linux viruses. You do not require protection for them. It is just a windows thing. No Linux system has ever had a virus. That is because Linux is not a bootable program. You can actually boot Linux from a floppy disk. Every time you boot it up it is sanitary. The biggest problem with Linux though from what I have heard is there is no compatibility with Windows at all unless you partition your hard drive and use half of it on Linux and the other half breed with Windows. You can not use modems, even simple dial up programs do not work. You have to script your own."

So is this guy full of it or is he right? I would really appreciate some input here, and some examples if possible.

The guy is full of shit. I am not "very knowledgeable on Linux", but I obviously know more than this guy does. So I'll dissect his statement one by one and show them why he's wrong.

There are no Linux viruses.

Bliss, OSF.8759, RST, Adm, Cheese, Mighty, Ramen, Slapper, Staog, Devnull, Adore, Lion, Winux, and the list goes on. In fact, any statement of the form "There are no [OS Name here] Virus" is completely absurd: All that needs to be possible for a virus to exist is for the OS to be capable of installing new programs. A virus, after all, is just a specific type of program. So the moment someone says "There are no [OS Name here] Virus yet", someone's going to go out and write a virus, just to make that first person sound like a jackass. There's even a guide on how to write viruses for Linux. The guy claims to know a lot about Linux, but he must not know a lot about Google, or else he could have done some research by typing in "Linux virus" and found out that there are indeed Linux viruses.

You do not require protection for them.

I'm not gonna mess with this statement too much, because of the term "require". You don't require protection from Virus on Windows either, it's just a good idea. You don't require oxygen, but it's helpful if you want to live. Etc.

It is just a windows thing.

That's similar to the first statement, except a bit more broad. There are also MacOS viruses, OSX viruses, BSD Viruses, Amiga Viruses, PocketPC viruses, PalmOS viruses, XBox viruses, etc. It's left as an exercise to the reader to find them (hint, remember how I typed "Linux virus" into Google's search page?).

No Linux system has ever had a virus.

False, by virtue of the list of Linux viruses I provided. When the guy or girl who wrote those viruses first tested them, he or she had to run them at least once to make sure they worked. And a few of them are known to be in the wild, so there are plenty of Linux systems that have had viruses.

That is because Linux is not a bootable program.

A "Bootable program" is a program that can run from the BIOS before an operating system is started. Many (but not all) distributions of linux does this. Therefore Linux does exist in the form of a bootable program. In fact, most of the time when you encounter Linux, it'll be as a bootable program. Linux as a non-bootable program is usually reserve for rare situations (such as running Linux from within Windows XP without an emulation layer).

You can actually boot Linux from a floppy disk.

This statement is true, but I just wanted to point out that it contradicts the previous statement.

Every time you boot it up it is sanitary.

Unless, of course, you have a computer that is capable of writing to the disk.

The biggest problem with Linux though from what I have heard is there is no compatibility with Windows at all unless you partition your hard drive and use half of it on Linux and the other half breed with Windows.

From what he's heard, eh? And he wants his hard drive to "breed" with windows, huh? The intent of this statement is probably mostly correct, but in formal logic, if one part of a statement is false, then the whole statement is considered to be false. The problem with this statement is the "at all" part. What this statement says is the compability between Linux and Windows is 0%, so they would not be able to interact in any way at all. But notice how they can both connect to the same Internet. That's because they both implement the same TCP/IP protocol. Notice how Windows files can be read by Linux. That's because drivers have been added to Linux to let them access FAT and NTFS disks drives, specifically to allow for more compatibility between Linux and Windows. Notice how when you load a CD full of porn and mp3s, it works both on Windows and Linux. Notice if you burn a CD on Linux, you can read it on Windows and vice versa. Notice the Wine Project which lets you run Windows program on Unix (and Linux) machines. While I wouldn't say the compatibility between Windows and Linux is 100%, it's way more than 0%. I'd say maybe 20-30%. The other misleading part about this statement is that partitioning your harddrive and installing Windows on one of the partition does not magically grant Linux with more compatibility to Windows. Rather, the what's going on is that your computer can now run Windows because Windows is actually installed. Maybe that gave your very knowlegeable Linux friend the illusion that Linux suddenly became more Windows-like?

You can not use modems, even simple dial up programs do not work.

Here's a guide on how to use modems on Linux. If you couldn't use modems on Linux, I'd imagine the guide would be about 10 bytes long (it would just contain "You can't."), but it's longer than that. It's about 18955 bytes long. So they must be talking about something, right? My guess is, they're talking about what you have to do to use modems on Linux, which would imply that you can, in fact, use modems on Linux. Just for a bit of overkill, here's a few more sites on using modems with Linux: LinModems.org, Setting up a Linux modem, Linux Modem Setup, Debian Linux Modem Configuration, Linux Modem Sharing how-to. Don't forget to try typing "Linux modem" into Google.

You have to script your own.

Script your own modem? As in, typing something on the keyboard to magically make hardware appear? I'd like your friend to teach me that trick! I'd script myself 20 new computers with the latest videocards and 4 gigs of RAM.

Oh, maybe he meant "script your own dial up programs". Well, yeah, the first guy to ever have Linux installed on a computer with a modem had to script his own dial up program. This must have been in like 1991 or something. Then, having written the dial up program, and being sure it worked because he could now connect to the Internet, he posted his program on said Internet for everyone else to use. Of course, the Linux-modem users couldn't actually download the program themselves, as they couldn't dial up to the Internet yet. But they either got a friend, or used a spare Windows box to get the program, loaded it up onto Linux, and now they could connect their Linux boxes to the Internet too. Somewhere along the way, someone said "Hey, why don't we include these dial up programs onto the installation CDs for Linux? That way, when they get the CD and install Linux onto their computers, they can connect to the Internet right away!" They did do this, and called the contents of the CD "distributions". There's the RedHat distribution, the Gentoo distribution, the Debian distribution, the Ubuntu distribution, and so on. All the "good" distributions now have dial up programs that work. If a distribution had a dial up program that didn't work, the user would say "This sucks", and get a different distribution instead. Fast forward to the year 2005, and now pretty much all distributions let you connect to the Internet right off the CD. All the distributions that didn't let you connect died off 'cause nobody used them. Survival of the fittest and all that jazz.

So in conclusion, that guy is full of shit and doesn't know what he's talking about at all.