"Right at the moment, the database is the stickiest part," presenting the greatest difficulty to change. said Bray. But it is easy to switch components such as the OS, he said. IBM's Jhingran, meanwhile, touted the use of open interfaces in enabling technology choice.

Olson disagreed sharply with his co-panelists about the ease of switching technologies.

"These guys are out of their minds," Olson said. The decision to switch an OS or upgrade is one that is not easy, he said. Switching platforms requires application rewrites even for PHP systems, according to Olson.

"If you're building a system that has to work, you are almost always locked into your lower-level technology choices," unless a user wants to undertake the pain of moving, Olson said.

Oracle, he noted, has integrated its applications and services but also collaborates with Zend for customers to build PHP applications deployed with Oracle technology, said Olson.