Cisco
The Cisco Unified Computing System (UCS) provides the server and networking components of the stack, with a new approach in providing stateless compute and unified fabrics for easier management and simplified but versatile networking options. It scales very easily, up to 160 servers per UCS domain and beyond with multiple domains, yet retaining a single point of management.
The software layer is provided by enterprise operating systems or hypervisors, with the options to deploy operating systems directly onto the servers, or deploy a hypervisor and build a virtualisation platform.