Red Hat has updated Enterprise Linux 5.7, which now includes several features from Red Hat Enterprise Linux 6.1. The operating system processors supports deployments on Intel, AMD, POWER and IBM System z architectures. New features for network bridging and LDAP features for autofs improve centralised management of user file systems in an enterprise environment. New fencing features boost cluster reliability in Cisco UCS system and VMware environments. New X.509 certificate-based Subscription Manager feature delivers Red Hat subscriptions and software services in a flexible, scalable, and secure way.
Source: https://thehackernews.com/2011/07/red-hat-enterprise-linux-57-released.html