IBM canceled a plan to release its own AIX version of Unix for Itanium servers and recently transferred a handful of programmers working on Linux for Itanium to work on Linux for IBM's Power server processors. "IBM is starting to cross the line between 'We're not necessarily Itanium's biggest supporter' to 'We're not really convinced Itanium has a role at IBM,'" Haff said. Red Hat sells Advanced Server as a $2,500-per-year subscription that includes access to the Red Hat Network management service, but the new quarterly update cycle reinforces the company's idea that customers are buying not a single software package but rather a constantly adapting product. Red Hat isn't alone. Sun, the dominant seller of Unix servers, releases updates to its Solaris version of Unix quarterly. And Microsoft has been trying, with some resistance, to move customers toward a subscription payment model.