Portable Applications (requires no installation to work) are not only useful to carry around-in your removable disk drive but also have the added advantage of not cluttering-up your operating-system with their dependencies and leftovers after uninstallation, commercial application VMWare ThinApp is the most widely used technology to create portable packages of conventional applications, but if you are looking for a free alternative to ThinApp we now have Cameyo - world's first free, open-architecture application virtualization platform.