There are many ways to launch Mac OS X applications, including the following:
Select the application in a Finder window and select the Finder's Open command (-O).
Double-click the application's icon.
Single-click an application's icon on the Dock.
Open an alias to the application, such as one stored in your Favorites directory.
Open a document of the file type that the application is set to open.
Drag and drop a document onto an application's icon (or an alias's icon).
Select an application's icon or alias and press -down arrow.
Launch the application from within another application. (For example, you can launch a Web browser by clicking a URL in an email program.)
Add the application to the Login Items window so it is launched automatically when you log in.
Launch the application from a script created by AppleScript or another scripting utility.
If you have used a Mac before, you have probably used many of these methods to open applications. Most of them are very straightforward and require no discussion. A couple of them, though less often used, can be effective techniques for quickly opening an application.
One of the most powerful methods?although it's underused by many Mac users?is to launch an application by drag and drop. Macintosh drag and drop is a function of the OS whereby you move information from one location to another by simply selecting it, dragging it to where you want it to go, and then dropping it.
The drag-and-drop approach is especially efficient when you want to open a document with an application that wasn't used to create it initially. For example, if you receive a plain-text file and double-click it, it opens in TextEdit. If you want to open it in Word instead, you can simply drag and drop the document onto Word's icon and Word is used to open the file. Otherwise, you would have to first open Word, use the Open command, maneuver to the text file, and then open it.
If the file type is compatible with the application on which you drag it, the application icon becomes highlighted to indicate that it is a compatible file.
You can force an application to attempt to open a document with which it is not compatible by holding down the Option and keys while you drag the document onto the application's icon. If the application is capable of opening files of that type, the file is opened. If not, either the application still launches but no document window appears or the document window appears and is filled with garbage.
You can also use drag and drop to open documents using applications installed on the Dock. Simply drag the file you want to open onto the icon on the Dock for the application you want to use to open it. If the application is capable of opening the document, its icon becomes highlighted. When you release the mouse button, the application launches and the document is opened.
If the drag-and-drop technique doesn't work, see "I Can't Drag a Document on an Icon to Open It" in the "Troubleshooting" section at the end of this chapter.
If a file opens, but its contents are "munged," see "When I Open an Application, What I See Is Incomprehensible" in the "Troubleshooting" section at the end of this chapter.