I started a feature request a couple of days ago on the WHMCS website to request that they make it compatible with our favorite hosting control panel. Please vote here: http://requests.whmcs.com/responses/ispconfig-3-compatibility It's time ISPConfig 3 gets integrated with WHMCS. The developers have more than proven that ISPConfig 3 is a Powerful and Secure hosting control panel. Please vote for this!
