The GNOME File Manager allows you to launch applications from the main window by simply double clicking your mouse on a file which has an application associated with it. You can change the way file types are handled by reading the section called GNOME Mime Types in Chapter 10
If the file does not have an associated application you can right mouse click on the file and select Open with from the pop-up menu. This will bring up a dialog which allows you to define the application which will launch the file. For example, if you want to edit my file names test.txt with Emacs (a popular text editor) you can right mouse click on test.txt and choose Open with. When you get the Open with dialog box simply type in emacs in front of the test.txt file name. When you press OK Emacs will open the file.
Figure 7-5. The Open With Dialog