Neil Smyth wrote:The CentOS Linux distribution is a remarkable case study of the unique power of open source software. In CentOS 6 we have an enterprise level operating system that is developed and maintained at great expense that we can download and deploy without having to pay any money. To fully understand the origins of CentOS, however, it is necessary to begin by talking about another Linux distribution.

Arguably one of the most highly regarded and widely used enterprise Linux distributions available today is Red Hat Enterprise Linux 6 (RHEL 6). 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. Whilst the source code to RHEL is freely available, RHEL is not free of charge. 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 6 is 100% compatible with Red Hat Enterprise Linux 6. In fact, CentOS 6 is essentially Red Hat Enterprise Linux 6 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 so if you plan to deploy Linux in a mission critical environment where any level of downtime is unacceptable then the Red Hat service is unquestionably worth the money. 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 extremely responsive and helpful experts who participate on the CentOS forums.

CentOS 6 Essentials is designed to provide detailed information on the use and administration of the CentOS 6.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, 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.