Third-Party Software

While modifying cPanel and WHM source code is prohibited by our EULA, there are many software packages included within cPanel and WHM that can be modified.

cPanel provides documentation on how to modify included third-party software, the source for third-party software, as well as documentation on the software, in /usr/local/cpanel/src/3rdparty/. The software is organized by license type (BSD, GPL, MIT, etc).

Note: There are also hooks in cPanel and WHM to support custom configurations; please read our hooks documentation for more information.

Patches

Within /usr/local/cpanel/src/3rdparty/:license_type:/, a patches directory exists with the patches applied to the third-party software of that license type.

Instructions for Customizing Third-Party Software.

For some software, we supply instructions on how to modify the software so that your customizations will not be overwritten by cPanel/WHM updates:

• Customizing Horde Groupware Webmail (supplied with cPanel 11.25.1 and later).
  • For instructions on customizing Horde versions included with cPanel 11.25.0 and earlier, see /usr/local/cpanel/src/3rdparty/gpl/README-horde
• Customizing SquirrelMail
  • These instructions are also located at /usr/local/cpanel/src/3rdparty/gpl/README-squirrelmail
• Customizing Roundcube