NIPAP

NIPAP does IP address management and nothing else, which is precisely the argument for it. Large prefix lists stay fast, the search is genuinely good, and the CLI, web interface and API all treat the same data consistently.

MIT licensed and free, Python with a Postgres backend, and no commercial tier of any kind. It has been quietly maintained for years by network engineers who wanted a spreadsheet replacement that would not turn into a full DCIM platform.

Choose it when address planning is the actual problem. NetBox models racks, cables, circuits and devices, and if all you need is IPAM, most of that surface area is overhead you still have to maintain. Solo operators and small networks: lighter and faster to live in day to day. Large teams already running NetBox: no reason to add a second system.

The catch is scope and pace. NIPAP will not model your hardware, and development moves slowly. Confirm it still fits your needs before building tooling that depends on its API.