Sometimes I need to install a particular setup for testing... I've used virtual machines for this. The ease of compartmentalizing the installation of unstable software and drivers made me wonder if there is a straightforward way to generate a new virtualized layer of my own machine, whenever I want to install a collection of potentially risky or unstable apps. Essentially, stack the installs using only files that would be changed or created in the base system to define the VM. That way, unstable setups and complicated special purpose configurations could be turned on and off as if they were layers of a photoshop image.