You are trying to install or open an app that didn't come from the Mac App Store but you got a message saying App can't be opened because it is from an unidentified developer. This is how you bypass it.
Mac OS X Moutain Lion and its Safari web browser sharing options allow you to share and send any web page vie email as a PDF attachment in a matter of two clicks.
If you are the kind of person you want to read what has been changed before updating an app you can disable the auto app update setting. Or enable if you want updates fully automated.
VirtualBox is a great free cross-platform virtualization program that enables you to run Windows, Linux, Mac OS X and other operating systems on you Windows, OS X or Linux computer.
We have already learned how to create a bootable OS X Mavericks USB drive using a third party app, this time I will show you how to create one directly in Mac OS X.
Mountain Lion enables you to set notification alerts to remind you of upcoming birthdays, tasks, meetings and other important events you might have in your calendar.