IBM is receiving plaudits for its enterprise server strategy after releasing the next version of its AIX Unix operating system to public beta, ahead of a commercial release in November.

The AIX 6 open beta reverses a previous policy of only issuing pre-release copies to select customers and is the latest installment of IBM’s plan to be the biggest Unix company in the world.

The AIX release taps into IBM’s Power6 processor, made available on System p servers from last month, but will also run on systems back to Power4-generation machines. Applications for AIX 6 are also intended to be backwards compatible with versions as far back as AIX 5.2.

Key features include Workload Partitions, a capability that IBM said cuts the number of operating system images that have be managed and supports AIX and both Red Hat and Suse Linux distributions. The complementary Live Application Mobility feature allows partitions to be moved without requiring the application to be restarted.

For security, Role Based Access Control allows administrators to create authorisation profiles for resource allocation.

In a statement, IBM System p vice-president Scott Handy said the open beta would let customers get to grips with new virtualisation capabilities and help in “speeding time to value”.

Gordon Haff of analyst Illuminata said, “I'd characterise this release as going a long way towards closing major feature gaps with its competition. IBM's System p is more directly competitive with HP than with Sun, given how much of Sun's attention is on scale-out boxes, whereas IBM is more focused on the higher-end systems. Certainly, that HP has been going through a product line transition to its Itanium Integrity servers hasn't helped HP any.”

Haff added that although the Unix sector as a whole is not growing, nobody should expect a rapid decline.

“Linux has captured the attention of developers and continues to grow [but] the traditional Unix market is still large and the big Unixes still mostly exceed Linux in technical sophistication and capability of handling the highest loads in large servers.”

Other watchers said IBM’s execution on the Power and AIX release schedules are giving it momentum.

“From a distant third in Unix five years ago, IBM is pretty much neck and neck with Sun and HP, if not a little out in front,” said Brad Day, principal analyst at Forrester Research’s IT operations group.

“This AIX release is the first time we’ve seen a clear set of movements to make the System p a mainframe replacement, and IBM has obviously learned from Sun’s playbook in opening up Solaris.”

Day added that many firms are now using System p servers to consolidate workloads with about a third of Forrester clients running Linux alongside AIX.