upsguru is a daemon that monitors a UPS connected to a serial port. It has been extensively tested with a rebadged Centralion UPS. It communicates with init via the /dev/ initctl FIFO in order to control system services in the event of a power failure. The sample scripts include commands for SMS notification using gnokii. Protocol details are also contained in the archive.
wmmge is a little dockapp for Window Maker which monitors an MGE UPS. It shows the remaining time, and it blinks if this time is short. It uses PSP (Personal Solution-Pac) monitor, which can be downloaded from the MGE website: http://www.mgeups.com. It needs root permissions to send messages to the UPS.
Power Daemon (powerd) is a daemon that can monitor a UPS and safely shut down the machine when the power is out. It can also notify other power daemons running on the network that the power is out, so they may also safely shutdown. It can automatically determine the UPS and cable configurations.