Caffeine for Windows - Prevent your computer from going to sleep
Caffeine for Linux - Inspired by the Mac OS X version, Caffeine for Linux is a status bar application able to...
Clapet - Clapet is a utility that aims to improve clamshell mode on your Macbook by automatically managing sleep when an external display is detected.
KeepingYouAwake - A Caffeine clone for macOS Yosemite, El Capitan and Sierra (including Dark Mode).
SmartSleep - SmartSleep lets you select each sleep state.
Caffeine by IntelliScape Solutions - Don't let your Mac fall asleep.