The Definitive Guide to User Mode Linux describes the recent addition to the Linux kernel that permits multiple, separate instances of Linux to run on top of Linux (just like any other user program). Running as user processes, instances of the operating system can provide virtual hosting, and can provide sandboxes, where each individual user actually controls his or her own Linux operating system (even though the underlying hardware is shared). User Mode Linux can also run different versions of the Linux operating systems at the same time.This book will assume a passing knowledge of Linux and system administration in general, but will not assume that the reader is an expert Linux user or administrator.