Oracle Linux
Oracle Linux, formerly known as Oracle Enterprise Linux, is a Linux distribution based on Red Hat Enterprise Linux (RHEL), repackaged and freely distributed by Oracle, available under the GNU General Public License (GPL) since late 2006.
Oracle Linux can be downloaded through Oracle's E-delivery service or from a variety of mirror sites, and can be deployed and distributed without cost. Commercial technical support is available through Oracle's Oracle Linux Support program, which supports Oracle Linux, and existing RHEL or CentOS installations (i.e. without reinstallation). As of 2013, Oracle Linux has over 11,000 customers subscribed to the support program.
RHEL compatibility
Oracle Corporation distributes Oracle Linux with two alternative kernels:
Red Hat Compatible Kernel (RHCK) – identical to the kernel shipped in Red Hat Enterprise Linux
Unbreakable Enterprise Kernel (UEK) – based on newer mainline Linux kernel versions, with Oracle's own enhancements for OLTP, InfiniBand, and SSD disk access, NUMA-optimizations, Reliable Datagram Sockets (RDS), async I/O, OCFS2, and networking.
