HP-UX is the UNIX-based operating system for the HP 9000 series of business servers from Hewlett-Packard. The 9000 series spans a spectrum of business needs and server sizes, ranging from an "entry-level" server appropriate for an Internet firewall, Web hosting, or branch office use to a midrange server appropriate for advanced enterprise resource planning (ERP) or Web commerce, to a high-end model for larger-scale and more computing-intensive applications. HP's SuperDome computer is based on parallel operation of up to 64 9000 processors. All of these servers run HP-UX.
HP also offers the e3000 line of servers, evolved from its long-established HP3000. The e3000 servers use HP's MPE/iX operating system.