Caffeine is a lightweight and portable utility that prevents your computer from going into idle mode, hence blocking lock / sleep operations or the launch of the screensaver.
Bearing a suggestive name, Caffeine won’t let your computer go to sleep, dosing it with a cup of coffee once in a while, metaphorically speaking. In computer language, it simulates a key press every 59 seconds, preventing it from locking or from triggering the system screensaver.
The application sits quietly in the system tray and displays a control panel if you right-click the icon. From here, you can activate or deactivate it, as well as configure the interval for keeping the computer alive (1 to 24 hours).
The icon, which depicts an actual cup of coffee, will appear empty if the application is disabled and full, it it’s enabled. When it’s active, it does not interfere with your work whatsoever and consumes very little resources.
If the default settings are enough for you, the software features support for various command line options, offering you an advanced way to customize its behavior.
As such, you can configure the application to simulate a key press at a different interval, one that you specify. Additionally, you can also set it to emulate the Shift key instead of the default F15 combination, to prevent sleep, but at the same time to allow the screensaver to launch, as well as to start the software disabled.
However, the command line mode is aimed at advanced users who have previous knowledge of similar approaches. Beginners are advised to make use of the tray utility, since the purpose is carried out nonetheless.
On an ending note, Caffeine keeps your computer awake for as long as you want and asks for nothing in return. By simulating a key press every 59 seconds, it prevents it from going to sleep, lock mode or from launching the screensaver.