APC UPS Daemon (Powerful Daemon for APC UPSs)
Controls and monitors the status of an APC UPS under Linux. Allows your
computer or server to run for a specified length of time on UPS power
then executes a controlled shutdown in the case of an extended power
failure. Find APC on the Internet at http://www.apc.com/.
APC also made their PowerChute plus available for download at