Banks worldwide are opting for the predictability and familiarity of Microsoft's Windows for application servers over Linux, according to a global financial services software company.

Sydney-based Financial Network Services (FNS) develops banking applications in the mainframe and Windows environments, for its "core" and "delivery channel" products respectively. The core applications run on zOS, Unix and Windows; however, the delivery channel products are Windows-only with the next generation being built around the .Net framework.

FNS sales and marketing manager, Robby Di Stefano, said the company's applications cover customer accounting, loans, general ledger, and branch systems.

Di Stefano said it's "not surprising" that 95 percent of FNS' business is overseas with the State Bank of India being a flagship account with 14,000 branches serving 90,000,000 customers.

FNS group product manager Dean Mathieson, said more banks are "choosing Microsoft [Windows] over Linux".

"Generally, every banking customer in the world already has Microsoft technology in their branches and regional offices," Mathieson said. "So deploying a .Net application is easier for the bank because it is usually deployed on existing systems and people are familiar with Microsoft environments."

Mathieson said Linux requires "Linux administrators and things like that" and with Windows "the administrators and technical teams already exist".

Although conceding many banks already have a lot of existing Unix skills, these are "not in the amount you would need to manage a large-scale Linux environment".

As previously reported by Computerworld, local banks including Adelaide Bank, the Bank of Queensland, National Australia Bank and Suncorp have made firm commitments to the Windows platform even in the midst of significant infrastructure overhauls.

"What we have started to find is that where Linux and Java probably came out with all guns blazing in the beginning, we have more banks now that are starting to choose a Microsoft platform, including one of our customers in the Middle East," Mathieson said.

"Their preference is for Microsoft products which are already fully functional. There is nothing you have to add to them. Once you install a Windows server you have everything you need to run our core banking system and deploy our branch system."

That said, Mathieson's development team is looking at the Mono Project to run .Net applications on Linux.

One area in IT where the banks are relying on Linux and open source is hosted transaction processing where 50 percent of BPayView customers have their statements delivered with Linux and open source systems run by CommSecure. According to the company this rate will soon increase to 75 percent.

Linux Australia president Jonathan Oxer said it is "unfortunately a fact" that Linux administrators are difficult to find right now, which may be swaying the banks' decisions to deploy it.

"This is a side effect of rapid uptake of Linux and its increasing popularity on the server and desktop," Oxer said.

"People with Linux skills are in high demand, but that situation should improve [because] organizations like the LPI [Linux Professional Institute] are experiencing a massive increase in demand for Linux certification."