This paper is published in 2011, regarding cloud computing and virtual machine management. In this paper drawbridge concept is introduced by Microsoft where the idea of picoprocess and library OS is reconsidered to modify the windows 7 operating system. Picoprocess is the isolation which is built from an OS process address space, but with all traditional OS services removed. The application binary interface (ABI) between code running in the picoprocess and the OS follows the design patterns of hardware VMs. Library OS provides the interface for applications to communicate with OS kernel. In this paper APIs are used to communicate between kernel and applications. Application binary interface is used as module to communicate between binary applications.


  • Reduce the hardware overhead and resource management for host and guest machine
  • Isolation between guest and host kernel
  • Providing secure way to communication between guest and host kernels and applications.


  • Reintroduced Library OS in windows 7 to provide secure interface for communication using APIs and ABI.
  • Provide isolation for guest and host kernel.
  • Resources are management to reduce the overhead
  • Increases the performance of applications in guest machine


  • It is a prototype research and it is far from production
  • Security is still a big issue

Extra Question:

High graphics application utilize large amount of resources and core APIs shall be required.