Sun Microsystems made released a new version of its venerable Solaris server operating system - expected to be the last release before the company's takeover by Oracle.

Enhancements include features that boost performance and lower energy consumption for servers powered by Intel's new Nehalem-class Xeon processors, and improvements to virtualization and storage.

The next major release of Solaris, version 11, is scheduled for the middle of next year, says Larry Wake, group manager for Solaris marketing at Sun. He declined to speculate on the fate of Solaris after the Oracle acquisition.

After buying Sun earlier this month, Oracle CEO Larry Ellison called Solaris "by far the best Unix technology available in the market" and the "heart of the business" for Sun.

Sun released Solaris in 1992 as a successor to its earlier SunOS. The then-proprietary operating system was historically tightly integrated with Sun's Sparc CPUs, though that has changed.

"We want to make sure Solaris runs well on the boxes we make, but also make sure it works on everybody else's systems," Wake said.

That commitment resulted in features tailored for Intel's new Nehalem CPUs such as a "power-aware dispatcher" that enables Solaris to aggregate workloads onto the fewest number of CPU cores needed and then turn off the rest, he said.

Solaris now can also offload network traffic processing from the CPU onto compliant network cards.

Sun released Solaris 10 early in 2005, the same time it announced a plan to gradually make the OS fully open-source. Its last major update to Solaris was in mid-2006, when it introduced its 128-bit ZFS file system and its Containers lightweight virtualization technology, and also bundled the PostGres open-source database.

Both ZFS and Containers were also updated with this release. ZFS now has a high-speed cloning feature that lets a new server point to existing data rather than copy and write a second, unnecessary time. That can speed up the creation of virtual machines under Containers, Wake said.

ZFS also can now recognise solid-state disks (SSD) and take advantage of their faster speed.

Sun officially released OpenSolaris last year. Some analysts speculate that Oracle might want to merge OpenSolaris with Linux. Wake declined to comment.