NoSleep is a free utility for Mac that allows you to close your MacBook's lid without putting it to sleep.
NoSleep doesn't really provide a user interface. It comes with a settings pane, that is accessible from the System Preferences. You can choose to disable sleep when the computer is running on AC Adapter or on Battery. Also, it provides the option to start the program on system startup. Besides the preferences pane, a menu bar icon is also supplied which allows you to enable or disable NoSleep's functionality.
You should use this application carefully. Sometimes it is not a good idea to have your computer running with the lid closed because some of the heat is vented through the keyboard and the computer can overheat.
Pros
- Free
- Easy to enable/disable
Cons
- Doesn't provide many features
This article discusses two different apps but calls it one. No sleep by limit point is commercial and costs 10 dollars and will not prevent computer sleep with lid closed. No Sleep by Prokofiev is freeware and allows the computer to stay awake with the lid closed. The badge displayed in this article is the Prokofiev badge but the user interface described is for the Limit Point program.