"We're slowing things down to cover customers who don't want to change so often," said Nick Carr, enterprise marketing manager, during a conference session yesterday at the Red Hat Summit in Nashville.

Contrary to individual PC users, who typically greet the latest operating system updates with open arms, corporations are often leery of upgrades for fear of introducing security holes or software crashes to hundreds or thousands of computers. Most engage in a testing or certification process before installing even minor updates, which can be labor-intensive.

Carr said that starting with the expected release of Red Hat Enterprise Linux (RHEL) 5 in December, major versions will come out closer to once every two years, compared with the prior rate of once every 18 months.

Moreover, Red Hat will release updates to major versions every six months instead of every four months. Red Hat will also support each update for 18 months after release, meaning companies installing RHEL 5.0 can keep getting support even if they skip versions 5.1 and 5.2, and jump to upgrade when RHEL 5.3 comes out a year and a half later.

"Users told us that they can't take every update because it involves too much certification, yet they still need the security fixes," Carr said.