In the interview, Christ said these legacy systems were revolutionary at the time they were built, replacing reservations held on a card index. Then came air-travel software systems such as Sabre, which coincided with the deregulation of the airline industry and the rapid growth of the business.

ITA, a developer of airfare pricing and shopping applications, has provided a fare-searching service to airlines for six years. Now it's locked onto bigger goals. The company has developed airfare-booking software that lowers processing costs to a few dollars per ticket, far below the $12 a ticket airlines pay reservation processors like the Sabre Travel Network. And CEO Jeremy Wertheimer sees opportunities to develop apps to help airlines modernize everything from reservation systems and call centers to gate operations and aircraft maintenance.

But buying and selling tickets is the focus for now. "Almost every ticket you buy is still being handled by assembler code running on a mainframe," Wertheimer says. ITA's applications run on inexpensive x86 PC hardware running Linux. That has caught the attention of major airlines, which see a chance to drive down costs and compete with low-cost carriers such as Southwest Airlines.

One of his group’s biggest projects is an upgrade of AA’s entire network. Previously, some 600 locations worldwide, such as airport counters and city reservation offices, were running on a proprietary, IBM Token Ring network. In the fourth quarter of 2000, they began replacing that with an IP network. That massive effort, which employed more than 1,000 people, involved the recabling of more than 50,000 hardware devices, 2,500 100MG Ethernet switches and a significant connection of wireless devices (using 802.11b) to the wired network in some 80 airports. As of June, 99.7 percent of the cabling in domestic locations had been completed. Wilcox believes the AA IT group’s work is central to American’s fortunes: "We’re in front of the business; we’re helping them figure out what’s possible and where they can go," he says.