Azure already has a very good hosting control panel however there may come a time when its more cost effective to host your own sites with a virtual machines.
We have used webMin which is Perl based but it tends to be unsuitable for running a web host like Azure or GoDaddy.
Froxlor is still a bit limited for a larger scale operationj which makes it unsuitable.
ISPConfig has 4 levels of as administrators, resellers, clients or email users. This is more structured for a larger operation as it can support multiple servers. It comes with support for software like Apache/Nginx, Postfix + Dovecot/Courier, MySQL, PureFTPD, Bind/PowerDNS/MyDNS and more.
For the point of view as webhost.com the ISPConfig seems to be the best choice for now. Generally websites need developers which complicates the matter considerably. cPanel is the best user front end at present.