Help me out! I'm compiling a list of billing systems that support Virtualmin.
I've collected a list of systems that have some sort of support for Virtualmin listed...but, we only have direct experience with WHMCS, so I wanted to ping the community to see if anyone has experience with any of the others, and can provide guidance on how they work (especially if you've used them with Virtualmin, but general comments about the billing system are welcome, too).
So, here's the list of systems I've confirmed have some level of support for Virtualmin:
Am I missing any?
Edited: Added ClientExec suggested by Diabolico. Edited Jul 29, 2017: Added Boxbilling.