From: https://spritelink.github.io/NIPAP/

Also: https://www.pcwdld.com/best-ipam-software-ip-address-management

A network engineers best friend
nipap is a sleek, intuitive and powerful IP address management system built to handle large 
amounts of IP addresses.

Python
Written in the world's most awesomest programming language. There's also a very convenient 
pynipap library for interfacing with NIPAP from Python

From: https://www.unixmen.com/install-gestioip-ip-address-management-tool-on-ubuntudebian/

GestióIP is an automated, web-based IPv4/IPv6 Address Management (IPAM) software. It features 
powerful network discovery functions 
      (mostly SNMP but will ping and do DNS lookup)
and offers search and filter functions for both networks and host, permitting Internet Search Engine equivalent expressions.