 There is the option to purchase the server with ClearOS installed in order for users to be able to enable applications via an easy-to-use web-GUI with minimal effort.ProLiant servers are separated into four main product lines - ML, DL, BL, SY, and Apollo - which generally denote form factor.The ProLiant ML line comprises tower-based servers (convertible to rack mount) with capacity for internal expansion of disks and interconnects, while the DL line comprises general purpose rack mount servers.