We use CWP (http://centos-webpanel.com/) for users who can't afford the current cPanel pricing, it provides almost all the features offered by cPanel. You can find the demo installation here: http://centos-webpanel.com/demo
The only downfall for this panel is that it doesn't offer the Reseller feature now. It has a FAQ page: http://wiki.centos-webpanel.com/ which will help you sort out any questions and if you've more to ask, then please make use of their forum: http://forum.centos-webpanel.com/