IBM claims its Linux business is growing at 65 percent a year, close to double the Linux adoption rate it says has been estimated by market researcher IDC.

The head of IBM's Linux software business, Scott Handy, told an audience at the company's Developerworks event in New Orleans that the growth is partly a result of hitting a market "sweet spot". But Handy also put it down to greater availability of Linux applications and the willingness of small- and medium-sized organizations to adopt them.

Handy's sweet spot is situated between Linux reliability and Intel processor price-performance. That translates into greater Linux scalability, shown at Developer-works in a demonstration of DB2 running on a 40-node Linux cluster.

On the application front, SAP is notching up some successes on Linux, numbering more than 1,000 customers, Handy said, up from about 200 in 2001.

Handy is responsible for promotion of IBM's own Linux-based applications as well as shared marketing and promotion of software sold by business partners. The marketing challenges are three-fold, he said.

The first is getting across the message that there is a wide variety of applications for Linux. Handy said that is not as difficult as might be thought: direct mail marketing that mentions a Linux software release averages two-and-a-half times the response of other direct-marketing software campaigns. And developer partners are coming to the party by deploying the company's 12-month-old Speed Start Linux development kit to create 6500 Linux server applications.

The second challenge, according to Handy, is getting across the message that companies are actually running business applications on Linux. There are now enough well-known users of Linux for serious business applications to provide good site references, says Handy. One he mentioned was Groehe, the German tapware manufacturer, which was running SAP on Linux.

Handy's last challenge is spreading the word that Linux is scalable enough to handle applications across the board, from small enterprises to large global organizations.

With much improved threading in the 2.4 release of the Linux kernel, and improved performance on multiprocessor machines, Handy said Linux would scale as far as you needed it to. He pointed to a 10-fold improvement in the performance of IBM's Domino under the 2.4 Linux kernel.

Symmetric multiprocessing under Linux worked well on machines up to around eight or 16 processors, said Handy, while clustering would scale up to 2,000 nodes or more.