This page is about navit as a virtual appliance. This means that you run a virtual machine, which runs navit itself.
This ofcourse will add some overhead.
On the otherhand if you have a machine that you cannot install software on, this virtual appliance might be a good method of running navit, without "installing" software.
I use qemu for the virtual machine. This program runs in userspace, so no "installation" is necessary.
Below are the general steps to install qemu, details can be added over time.