Red Hat will also provide maintenance for seven years after the release of each major version.

For those users who want updates as fast as possible, Red Hat recently introduced a feature in its Red Hat Network systems management software that allows subscribers to get non-critical fixes automatically delivered via the Internet once a week, Carr said.

Both RHEL 3.8 and RHEL 4.4 are due for release this summer, Carr said. Update 8 is the final update for RHEL 3, originally released in October 2003, and adds several device drivers. Update 4 to RHEL 4, meanwhile, adds meatier features such as support for InfiniBand networking, IPv6 and more, Carr said.

For the highly anticipated RHEL 5, which will include built-in Xen virtualization, Red Hat will release a beta test version to a limited set of partners and customers at the end of July, followed by a public beta in mid-September. Virtualization and other possible new RHEL 5 features will be available for preview via Red Hat's free open-source distribution, Fedora Core 6, Carr said.

Red Hat's services group will also begin offering a service to evaluate companies' readiness for virtualization after the release of the limited beta.