Apcupsd, short for APC UPS daemon, is a utility that runs on Linux, UNIX, macOS and Windows.

Apcupsd also works with some OEM-branded products (e.g. Hewlett-Packard) manufactured by APC.

[citation needed] As of version 3.14, Apcupsd has support for the PowerChute Network Shutdown function as well as many other features.

[1]: 34 Apcupsd runs in daemon mode so to keep a live connection with the UPS.

Depending on the settings and type of connection, Apcupsd either polls the UPS to learn about its current state, or receives messages from the UPS itself (e.g. via SNMP traps).