The next Linux distribution that IBM throws its weight behind is likely to be China's Red Flag Linux, suggesting that for businesses elsewhere in the world the Linux market will remain a two-horse race for the time being.

IBM wants to give its customers as much choice with Linux as it can, but the cost of porting and testing applications for more than the two leading distributions -- from Red Hat and Novell -- makes it impractical to widely support a third option, said Adam Jollans, IBM's worldwide marketing and strategy manager for open source.

IBM has around 300 software products. Supporting both Red Hat and Suse Linux effectively doubles the number for which it has to do testing. Adding support for its three main hardware platforms -- x86, and IBM's Power and zSeries -- means IBM has to test 1,800 software products. Adding broad support for a third Linux operating system, such as Debian, would take that number to 2,700.

"We're not ready yet to go to another multiple," Jollans said, during a discussion with reporters in Paris on Thursday.

Support from vendors like IBM and Oracle makes a big difference for the adoption of a Linux distribution. It gives big businesses the confidence that the software will be around and supported for several years to come.

The next distribution that IBM supports widely is likely to be one for the Chinese market, where the leading contender right now is Red Flag Linux, from Red Flag Software, Jollans said.

"We're watching China very closely to see what happens there," he said.

The company will support other distributions today but typically only for large customers or large installations.

Jollans also addressed a question about why IBM did not release its own Linux distribution several years ago.

"We thought that if IBM was in the market as an 800-pound gorilla, it would have a negative effect on the Linux market. We won't do something that sets us against the community," he said.

The IDG News Service is a Network World affiliate.