Of all of the industies deploying Linux and open source software, financial services have been among the earliest adopters. But what do banks and brokerages see in these emerging alternatives besides possibly lower up-front costs?

NEW YORK CITY (BetaNews) - A few years ago, financial services firms tended to point to low cost and customizability of components as their major reasons for turning to Linux and open source. But at the Linux/Open Source on Wall Street show today, panelists devoted more of their remarks to topics such as multi-OS server consolidation on mainframes and creating realtime Linux applications for PC servers, aptly reflecting the growing complexity of software environments in financial firms and elsewhere.

Citigroup, for instance, now plans to add Linux applications to a set of "core" Unix and mainframe apps recently consolidated on an IBM Z10 server, said Aaron Graves, the bank's senior VP for architecture and technology engineering, in a panel session.

Meanwhile, for his part, Head Bubba, VP of IT research and development for Credit Suisse, said that he is working on realtime Linux applications for traders.

Citigroup's Graves told the audience that, regardless of which platform an application is running on -- and regardless of whether it's "open source" or not -- what's most important to him is that it's well supported on the technical side by the software vendor or distributor.

Speaking with BetaNews later, however, Graves said that, in his opinion, the main benefit of Linux right now is that Linux appllications will run -- either virtualized, or not -- on virtually any hardware system, including X86 PCs and mainframes.

Credit Suisse's Bubba, meanwhile, views the main benefit of Linux as lying in its wealth of real-time applications.

Almost by definition, real-time applications are "deterministic," meaning that developers can more easily specify behavior and support service-level agreement (SLA) compliance, according to Keith Bright, another speaker. But realtime applications have traditionally suffered from a performance hit.

Over the past few years, the two major Linux OS distributors -- Red Hat and Novell -- have each added support for realtime applications, noted Bright, who is program director of IBM's Linux Technology Center.

Bubba, however, said that Credit Suisse is working on ways of coding Linux real-time applications so that performance isn't reduced.