ABSTRACT
Cooperative Linux, abbrieviated as coLinux, is software that lets Microsoft Windows cooperate with the Linux kernel to run both in parallel on the same machine. Cooperative Linux utilizes the concept of a Cooperative Virtual Machine (CVM). In contrast to traditional VMs, the CVM shares resources that already exist in the host OS. In traditional (host) VMs, resources are virtualized for every (guest) OS. The CVM gives both OSs complete control of the host machine while the traditional VM sets every guest OS in an unprivileged state to access the real machine. The term \"cooperative\" is used to describe two entities working in parallel. In effect Cooperative Linux turns the two different operating system kernels into two big coroutines. Each kernel has its own complete CPU context and address space, and each kernel decides when to give control back to its partner. However, while both kernels theoretically have full access to the real hardware, modern PC hardware is not designed to be controlled by two different operating systems at the same time. Therefore the host kernel is left in control of the real hardware and the guest kernel contains special drivers that communicate with the host and provide various important devices to the guest OS