cPanel is a Unix based web hosting control panel that provides a graphical interface and automation tools designed to simplify the process of hosting a web site. cPanel utilizes a 3 tier structure that provides capabilities for administrators, resellers, and end-user website owners to control the various aspects of website and server administration through a standard web browser.
In addition to the GUI, cPanel also has command line and API-based access that allows third party software vendors, web hosting organizations, and developers to automate standard system administration processes.
cPanel is designed to function either as a dedicated server or virtual private server. The latest cPanel version supports installation on CentOS, Red Hat Enterprise Linux (RHEL), and CloudLinux. cPanel 11.30 is the last major version to support FreeBSD.
Application-based support includes Apache, PHP, MySQL, PostgreSQL, Perl, and BIND (DNS). Email based support includes POP3, IMAP, SMTP services. cPanel is commonly accessed on port 2082, with an SSL-secured server operating on port 2083.
Once installed, cPanel cannot be removed (without extreme difficulty). The server must be formatted, and the operating system reinstalled. Similarly, it should only be installed on a freshly installed operating system with minimal prior configuration.
History
cPanel Inc. is a Texas corporation with primary offices located in Houston. The software was originally designed as the control panel for Speed Hosting, a now-defunct web hosting company. The original author of cPanel, John Nick Koston, had a stake in Speed Hosting. Web King quickly began using cPanel after their merger with Speed Hosting. After Speed Hosting and Webking merged, the new company moved their servers to Virtual Development Inc. (VDI), a now-defunct hosting facility. Following an agreement between John Nick Koston and VDI, cPanel was only available to customers hosted directly at VDI. At the time there was little competition in the control panel market with the main choices being VDI and Alabanza. cPanel 3 was released in 1999; its main features over cPanel 2 were an automatic upgrade and the Web Host Manager (WHM).
The interface for cPanel 3 was improved when Carlos Rego of WizardsHosting made what became the default theme of cPanel. Eventually due to internal problems between VDI and John Nick Koston, cPanel split into two separate programs called cPanel and WebPanel. WebPanel was the version run by VDI. Without the lead programmer, VDI was not able to continue any work on cPanel and eventually stopped supporting it completely. John Nick Koston kept working on cPanel while also working at BurstNET. Eventually Nick left BurstNET on good terms to focus fully on cPanel. cPanel has since been updated and improved over the years.
Add-ons
To the client, cPanel provides front-ends for a number of common operations, including the management of PGP keys, crontab tasks, mail and FTP accounts, and mailing lists.
Several add-ons exist, some for an additional fee, the most notable being Auto Installers like Installatron, Fantastico, SimpleScripts, Softaculous, and WHMSonic (SHOUTcast/radio Control Panel Add-on). Auto Installers are a bundle of scripts which automate the installation (and update of) web applications such as WordPress, SMF, phpBB, Drupal, Joomla!, Tiki Wiki CMS Groupware, Geeklog, Moodle, MagicSpam WHMCS, and ZamFoo. Fantastico is a popular Auto Installer but is losing market fast because of lack of updates and fewer number of scripts.
cPanel manages some software packages separately from the underlying operating system, applying upgrades to Apache, PHP, MySQL, and related software packages automatically. This ensures that these packages are kept up-to-date and compatible with cPanel, but makes it more difficult to install newer versions of these packages. It also makes it difficult to verify that the packages have not been tampered with since the operating system's package management verification system cannot be used to do so.
WHM (Web Host Manager)
WebHost Manager (WHM) is a web-based tool used by server administrators and resellers to manage hosting accounts on a web server. WHM listens on ports 2086 and 2087.
As well as being accessible by the root administrator, WHM is also accessible to users with reseller privileges. Reseller users of cPanel have a smaller set of features than the root user, generally limited by the server administrator, to features which they determine will affect their customers' accounts rather than the server as a whole. From WHM, the server administrator can perform maintenance operations such as compile Apache and upgrade RPMs installed on the system.
Enkompass
A version of cPanel for Microsoft Windows exists, titled Enkompass. As of October 15, 2011, Enkompass is being offered for free as development for the product has been slowed.
