Yesterday Ellison told a gathering of Oracle partners in New York that Microsoft had already suffered damage from one open-source product, the Apache web server.
He claimed Apache had displaced Microsoft's Internet Information Services (IIS) technology. "They had a virtual monopoly on web servers, and then they were wiped off the face of the earth. And it's going to happen to them again on Linux," he said.
However, Ellison's version of web server history does not tally with a survey by research and services company Netcraft, which shows Apache already gaining a lead in the web server market by the time IIS appeared in 1996.
Netcraft's figures showed that although IIS ranks second behind Apache, it has never gained more than a 35% market share.
Ellison's characteristically dramatic predictions came during a showcase event following Oracle's announcement last week of new efforts to spur independent software vendors' adoption of Linux.
The Oracle chief predicted Microsoft would also face a challenge to its Office suite. Once a viable Office alternative is available for Linux, "all hell will break loose", he said.
Ellison deemed the Sun Microsystems-backed OpenOffice.org suite "almost usable", and predicted that as such software becomes more robust, Linux will make inroads into the desktop market in price-sensitive regions such as China and India.
"It will take many years, but [Microsoft] will,eventually, have to compete. It'll be a whole new world for them. I'm looking forward to it," he said.
He also addressed the utility computing model being championed now by several major suppliers, most notably IBM, which is heavily promoting its "on-demand computing" vision.
Ellison said that suppliers are correct to focus on offering customers simpler ways to handle their IT infrastructure, but that they placed too much emphasis on hosted offerings. What should matter for customers is not whether their servers are located in their own data centre or in a supplier's; the real advantages of a utility, IT-as-a-service model is that it shifts the burden of installing and maintaining complex systems away from customers and toward their technology providers.
The advantages of a one-size-fits-most, mass-production IT model and of labour specialisation should have been obvious to IT buyers long ago, he added.
"The computer industry is finally moving from a cottage industry to an industrial industry. We're moving at breakneck pace toward the 19th century," Ellison quipped.