It would be theoretically possible to do it all in user-land (needing no direct kernel access), but for an arbitrary OS to work pretty much absolutely everything including the CPU would have to be emulated so it would be very very slow compared to bare metal. Think DOSBox and similar.

With changes to the guest OS it gets better: more can be done relatively native. Have a look at 'user mode linux' for a good example of that There were attempts to make this work under Windows but I think those projects died pretty quickly as people just used kernel mode vitualisers instead for efficiency so there wasn't massive interest (cooperative Linux is somewhere between: it works in a similar manner to UML but requires admin access). Portable software as a general rule is written in poor languages. AutoHotkey, AutoIt and NSIS are the three main languages in use, because they allow people to moderately easily produce not enormous binaries and have a surprisingly low initial learning curve (though later on you hit plenty of walls with them; none of them is suited as a general purpose programming language). Prada Serial Number Search. I speak this as the developer of the PortableApps.com Launcher, which I did in NSIS as the launchers already in use were NSIS, and as size matters a lot (that killed things like Python outright, though using the RPython parts of PyPy with the garbage collector ripped out would have worked---I checked it out and was able to successfully compile. That would actually be very easy to create.

Most Linux installers are happy to install to a USB stuck and most PCs with happily boot from one. Download Free Software Oregon Trail 2 The Pirate Bay Site. I have a working Debian setup install on a large stick, created form the standard install procedure, that I use for diagnostics - adding vbox (or KVM or Xen or.) to that would be the same as adding it to any other Linux setup and you could then add a set of VMs that can be selected to start automatically on boot (rigging the boot process as needed to give you the choice at the appropriate point).