QEMU-Puppy is an OS and a set of applications on a USB memory stick.
Once upon a time, I realized that having your data on a USB memory stick wasn't exactly what I wanted. I wanted more. Carrying your files is nice. Carrying your applications as well would be even better. What the heck, carrying your OS and even your own machine on your memory stick would be the best!
If you have your files on your memory stick, you can take any machine and access those files. Being able to handle the files, depends on the installed software. If you don't want to depend on the installed software, you can put your own software on the memory stick as well. But most of the software needs to be installed, which is not easy, or possible, or desirable, or allowed on a lot of machines. You don't want to pollute a machine you borrowed... Having a complete OS at hand, including applications and files would take away these constraints. Just put everything on a USB memory stick and boot from it.
A bootable USB memory stick has some disadvantages as well. First of all, not every PC is able to boot from USB. Second, if the machine does boot from USB, not all hardware is detected or configured properly, since the hardware "changes" every day. Third, booting from USB "locks" the machine: It's either the natively installed OS or your OS, not both at the same time.
To get rid of these disadvantages, you can carry your own machine as well, not just your files, your applications and your OS. You can do this by buying a laptop. But it's expensive, a physical burden and risky. The USB memory stick is cheap, light and easier to protect. A virtual machine , like QEMU, is cheap, light and easy to protect as well. With such a virtual machine, we are able to boot our OS on top of the natively installed OS. Now we have two OS's running concurrently on one machine!
ALT-TAB is enough to hide your machine and get back to work...
The tricky part is trying to have the OS on your USB memory stick to be able to boot natively, as well as in a virtual machine. But it can be done. And that's what this document is all about...