Network UPS Tools - The primary goal of the Network UPS Tools (NUT) project is to provide reliable monitoring of UPS...
UPS Assistant - UPS Assistant
WinNUT-Client - This is a NUT windows client for monitoring your ups hooked up to your favorite linux server.
BatteryMon - BatteryMon is a battery monitoring software solution.
Cockpit Project - Makes it easy to administer Linux servers via a web browser.
coconutBattery - With coconutBattery you are always aware of your current battery health. It shows you live information about the battery in your Mac and iOS devices (iPhone, iPad)