And they are doing so "in a coexistence fashion," running Fusion alongside their existing Oracle business software, such as E-Business Suite, and looking to add more Fusion modules over time, said Chris Leone, senior vice president of applications development, during a keynote address.

Fusion Applications were Oracle's first to be designed specifically for cloud-based delivery, not only to give customers the option but to help Oracle itself run a SaaS (software-as-a-service) business profitably and more easily, Leone said.

For one, Fusion Applications have an extensibility layer that allows "upgrade-safe" tweaks to the user interface and process flows, a crucial component for any SaaS vendor, since major updates are applied to many customers at once, allowing for substantial cost savings.

Oracle is giving customers on its older ERP (enterprise resource planning) product lines software license credits for "like-to-like" functionality when they switch to Fusion Applications, Leone said after the keynote. Customers can also work with Oracle to factor and credit money they're now spending on annual maintenance payments into the cost of SaaS subscriptions for Fusion Applications, he said.

An IT professional who has worked with Fusion Applications said SaaS is the way to go, at least for now, given the headaches of running it on-premises.