The talk is about operating system virtualization technology known as OpenVZ. This is an effective way of partitioning a Linux machine into multiple isolated Linux containers. All containers are running on top of one single Linux kernel, which results in excellent density, performance and manageability. The talk gives an overall description of OpenVZ building blocks, such as namespaces, cgroups and various resource controllers. A few features, notably live migration and virtual swap, are described in greater details. Results of some performance measurements against VMware, Xen and KVM are given. Finally, we will provide a status update on merging bits and pieces of OpenVZ kernel to upstream Linux kernel, and share our plans for the future.