Neil Smyth wrote:Arguably one of the most highly regarded and widely used enterprise Linux distributions available today is Red Hat Enterprise Linux (RHEL). It is considered to be amongst the most stable and reliable operating systems and is backed by the considerable resources and technical skills of Red Hat, Inc. Red Hat Enterprise Linux is also an open source product, meaning that anyone can access the source code to the operating system and modify it as they see fit. RHEL is not, however, free. In order to get a binary copy of this operating system you have to purchase it as part of a service agreement that includes technical support.

CentOS is a testament to the unique nature of open source software because it is actually 100% compatible with Red Hat Enterprise Linux. In fact, CentOS is essentially Red Hat Enterprise Linux with the Red Hat branding and logos removed. CentOS is available for free so you get the power and stability of Red Hat Enterprise Linux without having to purchase it.

Of course, CentOS lacks the dedicated and guaranteed technical support that you get by buying a Red Hat subscription. That said, CentOS is backed by a skilled and active community and I have yet to encounter a problem with CentOS that could not be resolved with the help of the experts who participate on the CentOS forums.

CentOS Essentials is a book designed to provide detailed information on the use and administration of the CentOS 5.x Linux distribution. For beginners, the book covers the basics of configuring the desktop environment, resolving screen resolution issues and configuring the email client to send and receive email messages via web based services such as GMail. Installation topics such as dual booting with Microsoft Windows and configuring wireless networking are covered together with all important security topics such as configuring a firewall.

For the experienced user, topics such as configuring email and web servers, Xen and KVM virtualization, Secure Shell (SSH), remote desktop access and file sharing are covered in detail to provide a thorough overview of this enterprise class operating system.