WHMCS - WHMCS is an all-in-one client management, billing & support system for online businesses.
ManageEngine OpUtils - ManageEngine OpUtils is an IP address and Switch port management software that includes a comprehensive set of 30+ tools that helps network engineers monitor, diagnose and troubleshoot their IT resources.
HostBill - HostBill is a powerful and flexible, all-in-one automation, billing, client management and support platform for online businesses.
BlueCat DDI - Unify your DDI (DNS, DHCP and IPAM) solutions to make DDI data an engine for innovation and growth.
Blesta - Blesta is professional client management, billing, and support software.
phpIPAM - phpipam is an open-source web IP address management application (IPAM).