The big loser may be Hewlett Packard (HP) as Optus' moves away from its hardware and services in favor of IBM and Red Hat, respectively, the source said. While Optus has "only a few" in-house Linux specialists, its team of over twelve Unix specialists are being cross-trained in Linux reflecting the company's desire to migrate off its remaining "legacy" Unix systems.

Optus still has AIX, HP/UX, Solaris, and Tru64 installations, and although still deploying "some" Solaris and AIX, its emphasis is on Linux which now comprises "up to half" of all its Unix servers.

"A large part of Optus' push to Linux is cost savings in software and ongoing management," the source said. "It's costing Optus less to manage 100 Linux servers than the same number of Windows or Solaris servers."

The source said performance is "not an issue" and Optus is generally happy with the reliability of Linux.

Optus' general manager of IT program management Stuart McDonald said the company uses Linux "in many capacities" and does not have a preference for suppliers.