Others said that despite the apparent bounty of open-source stacks, they don't begin to meet the particular needs of many companies. "Many open source stack providers can only afford to support the most popular open source components. There are so many open source projects that no single vendor can assemble the expertise to meet every customer need," declared The 451 Group in an August report critical of open-source stack providers.

One firm trying to do something a little different is Simula Labs. Led by Damarillo, who founded and sold open-source application server vendor Gluecode Software Inc. to IBM in 2005, Simula provides enterprise support for open-source software. But rather than being just another MySQL, JBoss or Apache support provider, Simula is supporting technically sound but more niche-oriented products. In the process, it is getting in front of senior IT managers right away.

"With Gluecode, we used to have it sneak into departments," Damarillo said. "With Simula Labs, we're starting with the CIO."

Simula Labs emerged from stealth mode last week with support for four open-source applications. It has already signed 50 contracts worth an average of $80,000 per year with 20 mostly large organizations, according to Damarillo. Those deals include the State of Colorado and the National Institutes of Health.

Others, such as Troan, argue that customers who buy into open-source stacks can become as locked in as if they had bought a closed-source stack. They become afraid to deploy new applications "for fear you could break 50 other applications," he said. He claimed that rPath's software appliances grant customers the same easy deployment promised by stacks -- without those downsides. Besides Ingres, SugarCRM Inc. and open-source VoIP provider Digium Inc. are offering their software via rPath appliances.