NeoBill is a Web-based customer management and billing solution designed for Web hosting providers, particularly hosting resellers. It can create invoices, manage domains, and provides other services. It has an API for CPanel and for Domain Registrare for automatic domain registration.
ISP-fW is a firewall script which provides port forwarding, packet filtering, stateful packet inspection, port redirection, masquerading, SNAT/ DNAT, TOS, and generation of htb rules for bandwidth management. It includes a Web interface for easy access. It's useful for ISPs which want to separate National traffic from International traffic.