This is the first major release of RHEL since September 2003. This also will be the first version of RHEL based squarely on the Linux 2.6 kernel.

Novell Inc. first released its Linux 2.6-based server operating system, SLES (SuSE Linux Enterprise Server 9), in August 2004.

The actual gold code for the operating system has already been finished and is in the hands of a few developers. Several of them report that the next version of RHEL is based solidly on Red Hat's experimental Linux, Fedora Core 3.

Click here for a review of Fedora Core 3.

"RHEL 4 is Fedora Core 3 with new logos," one programmer with access to the gold code said. "I can even use third-party [software] packages for FC3 [on RHEL 4]."

There are some differences, though. The latest version of Fedora runs on the Linux 2.6.10 kernel, while RHEL 4 will use the 2.6.9 kernel.

Developers tell eWEEK.com that the system is very stable.

Among other features, the new RHEL will boast improved support for SELinux, the National Security Agency-based Mandatory Access Controls security subsystem for Linux.

In this new version, SELinux is enabled by default with a new "targeted" policy that locks down only a few typically vulnerable system services, such as Bind and Apache. In addition, there are tools that make adjusting SELinux's security policies much easier.

For an interface, RHEL 4 comes with both KDE 3.3 and GNOME 2.8.

It also will have Evolution 2.0 for its default mail client. In addition, it comes with the Firefox Web browser and the Thunderbird e-mail client.

Perhaps the most significant changes in this server distribution will be in its revised I/O (input/output) system and LVM (Logical Volume Manager). These improvements will increase the system file I/O performance and let it address petabytes of data. This, in turn, will make RHEL 4 much more attractive for massive database work.

RHEL pricing is expected to remain the same.

Check out eWEEK.com's for the latest open-source news, reviews and analysis.