Being based on the recently released Red Hat Enterprise Linux 6.3, Oracle Enterprise Linux 6.3 ships with two sets of kernels: an unbreakable enterprise Linux 2.6.39 kernel, and a Red Hat compatible Linux 2.6.32 kernel, both installed by default. In Oracle Enterprise Linux 6.3, the Unbreakable Enterprise Kernel has been greatly improved by Oracle, including extended functionality and bugfixes.