Operating-system-level virtualization, also known as containerization, refers to an operating system feature in which the kernel allows the existence of multiple isolated user-space instances. Such instances, called containers, partitions, virtualization engines (VEs) or jails (FreeBSD jail or chroot jail), may look like real computers from the point of view of programs running in them. Programs running inside a container can only see the container's contents and devices assigned to the container. Operating-system-level virtualization is commonly used in virtual hosting environments, where it is useful for securely allocating finite hardware resources among a large number of mutually-distrusting users.
At enlyft, we use sophisticated, patent-pending algorithms to track the use of various OS-level Virtualization (Containers) products and technologies. We track 8 products in the OS-level Virtualization (Containers) category, and have found 50,758 companies using these products.