When you double click on a file, your Mac opens it with the default application associated with it. For example, if you double click on a PDF file, 'Preview' will open. Sometimes you may have a need to open a file in a different program, instead of it's default. I use this tip daily when I am editing the screenshots for these visual guides. Let's get to it: Find the data file you want to open, and if you have a 2 button mouse right click on it, alternately, you can hold down Control and Click on the file. A contextual menu will pop up, and then you can choose 'OPEN WITH'. Here, OS X is smart, it knows the types of programs you have on the system, and suggests ones that are compatible with that file format, and provides you with a list. Now, if the program you want isn't on the list, choose 'the 'OTHER' option at the bottom of the menu, and you can navigate to the program you want. Click 'Open' and you file will open up with the your selected application.