I've been looking at a very interesting variant of Linux called Damn Small Linux, (hereafter called DSL). Its 3 major contributors have basically taken a minimalist approach to Linux and have created a system that can provide a basic desktop running on an OS that's right around 50 Megabytes. To enable more functionality, they have created a means of temporarily mounting “extensions” that are basically modified Linux applications like OpenOffice and other apps.
There are a number of ways to run DSL. The Official Damn Small Linux Book comes with a LiveCD that also has the means of burning a customized-by-the-user version onto another CD, installing it on a USB flash drive, running it in a VMPlayer window and another way of running it is in a cmd window under Windows! Needless to say its very intellectually beguiling simply because it offers an excellent way to operate small SBCs or old CPUs with Linux.
I have played with it a little bit and its amazing how fast a 600 Mhz P3 can run when its not having to drag around Windows baggage or a large Linux OS install. There are a couple of user interface issues that take a little getting used to. A right click on the desktop opens up a new menu of applications to run in place of a menu bar across one edge of the desktop. You'll get over that quickly when you see how fast the application will pop-open.
One of the means of operating DSL is as a RAM drive image. This allows for a fixed read-only operating system image that flat-out can not be written to. A second RAM “drive partition” is set to be the data storage and user profile settings record. The system image can simply be restored by re-booting the computer. For industrial applications this is the dream system setup. The user is allowed to make whatever temporary setting changes he wishes but they get wiped and replaced with the default setup on the next boot. Perfect!
Because the size is so freaking small, it should run on a relatively new SBC with 1 GB of RAM like a scalded dog!* Now all I have to do is figure a way to optimize our company's applications to operate without having to write to the read-only drive image. Yeah I know. I've got a lot of work ahead of me. Its going to be interesting to get a operating system and installed application image below 200 MBytes again.
* Please don't "rat" me out to PETA. Its only an expression!