"We have two data centers and have taken a different approach to the banks in that our data centers are effectively hot," Haig said. "So disaster recovery is more real-time and our terminals are able to contact multiple locations to get service."

MoneySwitch will import Eftpos terminals from Belgian company Banksys, which is one of only a few in the world that run Linux and Java on the device and supports native encryption. Within two months it had a prototype payment application running on the terminal.

MoneySwitch's network is purely IP-based and the terminals can access the transaction backend over GPRS, Ethernet, and Wi-Fi.

All this low-cost infrastructure is aimed at breaking the big four banks' "quadopoly" on the A$1 billion (US$766 million) transaction processing market.

"The ability to choose between open source projects and fit one in on top of another very quickly was a really compelling attribute as well as the cost, support and the reliability," Rothwell said. "It was a no-brainer for us."