For the original questions, I think it's been established that the kernel is what is required to define it as "Linux."

As for the smallest Linux computer, (by the definition above) it would be the smallest device running the Linux kernel, or some variant of it. And that's harder to track than you might think. Electronic devices are everywhere. And anything with a processor could (potentially) run a Linux kernel. There's no easy way to tell.

Android should be considered. I have installed a console app on my tablet, I can go in do nearly anything from the command line on my Android tablet as I can my laptop running a Linux distro other than any parts they left out for space.
That being said there are plenty of small systems running Linux. Raspberry PI, GumStix, etc. http://linuxgizmos.com/ lists many, take your pick and decide how exactly you want to define a computer.

In case anyone missed it, I think this must be a contender:
https://www.linuxquestions.org/quest...et-4175506141/

The Zaurus 3100 / 3200 IS the smallest PC with Linux world-wide !!

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Thats not all that small.
The OP needs to define what he's calling a computer. Is an SBC a computer or is he/she including the input/output?

It is not that small. It is actually the smallest Linux machine.

I remember that Android is not Linux, otherwise we would not install Debian everywhere on any devives (or other Linux distros)

What I'm saying is there are many Linux machines smaller than that, the raspberry Pi is smaller for example. It all depends on what your are including in the definition of a computer, are you including a display?

You are comparing completely different things. The Pi has no housing.
Opened the zaurus is smaller than the PI.: http://www.penguin.cz/~utx/zaurus/ww...urus/wireless/

Furthermore, to compare, one shall take the volume: http://en.wikipedia.org/wiki/Volume

If you compare mainboards without housing then post #18 should be the winner (for now).

It runs Android or Linux, where actually Android is not Linux.

Actually it was meant WITH a display or whatever it might be to display.

There are many housings available for the Pi.
Thats why I asked to specify your definition of a computer, is it a processor, a mainboard/SBC, does it have to have a housing, does it have to have output and/or input?
Does it need to be an end user product or a development kit?

But you would say that Linux is Linux, wouldn't you?
I certainly can run Android x86 and Linux on my desktop PC, so it is not qualified as a Linux PC anymore?

Anyways, if a display has to be part of the package you can have a look at this: http://jolla.com/
Sailfish OS is a Linux distribution not based on Android. Also, phones running with Ubuntu Phone would qualify.

I do not consider Android to be Linux.
Google is Linux, so, why cannot we call Linux instead of Google, then? ... and so.

Linux is Linux: Debian, Ubuntu,...

Wait, Google != Linux. Google is a company whose primary product is a search engine. They may use Linux on their servers but so might $big bank$ and you won't say $big bank$ is Linux. Google owns Android which is a modified Linux Kernel with a JVM.

The chip I posted will, it would appear, run "real Linux" as well as Android if the use wishes.
I don't know that it could claim to be the smallest Linux computer but I bought a Raspberry Pi the other day and I have to say that having raspian on it makes it a doddle to so that things I want as I've done them all before on real or virtual Debian instances on my desktop. To me that's why I don't thonk of Android as "real Linux" because it's too far away from just using apt-get, yum, slackpkg, compiling from source or other familiar install methods.