What are some alternatives?
When comparing ISPConfig and CyberPanel, you can also consider the following products
cPanel - With its first-class support and rich feature set, cPanel & WHM has been the web hosting industry's most reliable, intuitive control panel since 1997.
Webmin - Webmin, Usermin, Virtualmin, Cloudmin, Linux, System Administration
Vesta Control Panel - – What I love about Vesta is that it's fast and easy to use
Ajenti - Web administration panel for servers and custom hardware
CentOS Web Panel - Free CentOS Linux Web Hosting control panel designed for quick and easy management of (Dedicated & VPS) servers without of need to use ssh console for every little thing
Virtualmin - It includes numerous features not in the GPL version (like script installers, resellers, HTML editor, an improved UI, mobile access, spam and virus filtering).