A user-mode port of the Linux kernel

The Linux kernel has been ported so that it runs on itself, in a set of Linux processes. The result is a user space virtual machine using simulated hardware constructed from services provided by the host kernel. A Linux virtual machine is capable of running nearly all of the applications and services available on the host architecture. This paper describes the capabilities of a user-mode virtual machine, the design and implementation of the port, some of the applications that it lends itself to, and some of the work that remains to be done.