Network UPS Tools (also known as NUT) is an extremely powerful and versatile client/server based approach to UPS monitoring. Products from a wide range of vendors (APC, Belkin, Best Power, MGE, Tripp-Lite, etc.) are supported. A shared UPS can be monitored by one host, notifcations being sent to the other hosts via authenticated TCP connections. A Web interface is available, as is a Windows client.
asapm is an AfterStep look & feel Advanced Power Management (APM) monitor for laptop and notebook PCs running Linux or FreeBSD/NetBSD/OpenBSD and X Windows. It displays charge left in the battery, the time left to the total discharge of the battery, computer is connected to the mains or is working on a battery and the battery status high/low/critical.
Suspend2 allows you to hibernate your machine without needing APM, BIOS, or ACPI support. It creates an image that is saved in your active swap partitions, swap files, ordinary files or (soon) across a network. At the next system boot, the kernel detects the saved image, restores the memory from it and then it continues to run as if you'd never powered down.
TrinityOS is a step-by-step, example-driven HOWTO on building a very functional Linux box with strong security in mind. TrinityOS is well known for its strong packet firewall ruleset, Chrooted and Split DNS (v9 and v8), secured Sendmail (8.x), Linux PPTP, Serial consoles and Reverse TELNET, DHCPd, SSHd, UPSes, system performance tuning, the automated TrinityOS-Security implementation scripts, and much more.
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.
bpowerd is a daemon and makes proper use of the system log for error checking. It uses init's powerstatus calls to do it's dirty work, instead of calling shutdown itself. bpowerd is easy to compile and configure, using GNU's autoconf and providing explicit instructions for testing and installation. bpowerd was created using specs provided from the manufacturer, as opposed to reverse-engineering.