Caffeine (for Mac)
Caffeine is a handy, free Mac utility that keeps your computer in an active state when it would normally slip into powered down state.
Mac users who like to preserve every ounce of their notebooks' charges, or like to keep prying eyes away from their desktops, benefit from setting their computers to fall asleep, dim the screen, or launch the screensaver after a set amount of time. There comes a time, however, when you may want to temporarily disable those features without digging through OS X's system preferences.
That's where Caffeine (free) comes in to play. Caffeine is a Mac utility that sticks an icon in the right side of your menu bar, and prevents your Mac from automatically going into a rest state. Caffeine is available for download from both the manufacturer's website (http://lightheadsw.com/caffeine/) and the Apple Mac App Store. The tiny program, featherweight at 0.3MB, is a lightning-fast download for anyone with a decent internet connection, and a useful tool to boot.
Taking a Shot of Caffeine
I performed three experiments to test caffeine's ability to keep a Mac awake. I set the computer to fall asleep, dim the screen, and launch the screensaver after a minute's time. Caffeine, after I clicked its icon, kept the computer awake each time. I like that you can tell whether Caffeine is running by checking to see if the coffee cup icon is full (activated) or empty (deactivated).
Caffeine's one drawback is that it doesn't prevent a closed laptop from going to sleep, dimming the screen, or launching the screensaver. When I lowered the laptop lid and raised it a few minutes later, I heard the hard drive spindle swirling awake.
Make It a Double
Caffeine is a small, but useful OS X utility that lets you stave a computer's nap time with a simple icon click—no need to dive into Preferences to alter the system settings. Admittedly, Caffeine is a niche app, but if the idea of it appeals to you in any manner, it's worth a download.
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