Ubuntu 8.04 LTS Server Edition, only the second Ubuntu release aimed at servers, will be available for free download on Thursday, and features performance, stability and security improvements, according to Canonical.
Canonical also announced that the platform has been certified on several Sun x64 servers, including the Sun Fire X2100 M2, X2200 M2, and X4150.
The company said Ubuntu 8.04 LTS Server Edition, which comes with five years of maintenance and support, is designed for both enterprises and application makers who need a stable platform to plan around.
"Ubuntu 8.04 LTS is at the centre of a growing ecosystem of applications that serve businesses of all sizes extremely well," said Canonical chief operating officer Jane Silber, in a statement.
The server includes more network-infrastructure applications than the previous edition, 6.06 LTS, including authentication tool FreeRadius, monitoring tool Munin, VPN tool OpenVPN and backup tool Bacula, Canonical said.
The kernel has been additionally hardened, and AppArmor policies have been integrated. The server integrates host firewalling, features additional storage technologies, including iSCSI and DRDB, and includes more than 500 maintained and supported server packages, according to Canonical.
The new version adds the KVM virtualization technology, and kernel improvements mean the server uses resources more efficiently when under virtualization, Canonical said. The system integrates with Microsoft's Active Directory, via technology from Likewise Open, and is the first distribution to optionally include Sun's OpenJDK Java development kit, the company said.
Ubuntu recently appeared in a Yankee Group reliability survey for the first time, with 22 percent of respondents saying they had at least one Ubuntu server on the network. Users reported 1.1 hour of downtime per server, per year, a favorable showing in relation to other Linux distributions.
In February, Canonical chief executive Mark Shuttleworth revealed that the name of the version of Ubuntu due in October, version 8.10, will be "Intrepid Ibex", and that it will focus on pervasive internet access.
ZDNet.co.uk's Tom Espiner contributed to this report.