Insomniate - Insomniate is a highly lightweight application that keeps your PC from going into Sleep/Standby mode.
Caffeine for Linux - Inspired by the Mac OS X version, Caffeine for Linux is a status bar application able to...
Caffeinated - Caffeinated is a clone of a comparative Mac OSX apparatus called Caffeine and stops your PC going into standby.
Caffeine for Windows - Prevent your computer from going to sleep
noblackout - Disables screensaver and powersaving while running programms from a choosen directory.
Sleep Preventer - Prevents your computer from going to sleep, hibernate, dim the display or start the screensaver.