WHMCS is widely used hosting billing and support system. Currently WHMCS 5 is in production. WHMCS 6 is in current development and they released a beta version before few days ago.
WHMCS 6.0 is a major new update with a lot of new features and functionality, as well as many under the hood improvements. In WHMCS 6, there will be new interface to manage cPanel accounts directly from WHMCS. This will allow end users to quickly manage their cPanel account directly from their billing area. As per WHMCS blog, the new cPanel hosting account user interface will be as follow:
WHMCS 6 new cPanel user interface will also allow web hosts to promote the addon services (i.e. SSL certificate and other addons).