Hewlett-Packard's (HP's) Non-Stop, Red Hat's Red Hat Linux, and MySQL's namesake database are part of Sabre Holdings configuration for a system used by airlines, travel agents, and passengers to find and book flights. Sabre is working in phases to replace ancient mainframe assembler code with modern languages that run on low-cost commodity computers and open systems, including Linux. The Sabre Global Distribution System, formerly called the Customer Reservation System, goes back as far as 1960 and has three air-travel subsystems (for shopping pricing; booking; and fulfillment/day-of-travel operations). Progress in development should proceed at an even and safe pace toward the goals of more capability, open systems, a service architecture, distributed components, and much lower cost. Industry directions over the past two decades or more have required much innovation, but technical advances and Moore's Law allowed Sabre to assemble a scalable, powerful server form that uses commodity processors and huge amounts of memory. Open Systems meant migration from the proprietary and costly TPF environment to UNIX and then to Linux. Such standards as Common Object Request Broker Architecture (CORBA), Lightweight Directory Access Protocol (LDAP), and Java have allowed Sabre to base the shopping engine on a distributed and very flexible service architecture. Sabre is now closer to the end of its four-year migration than to the beginning. The new ATSE architecture makes changes easier and less costly. Three modules are connected by a LAN, and a front-end rules engine runs on 16-two-way HP Linux servers to perform as a master controller for the system that coordinates services and I/O over the LAN.