Versions 10.7 and later of the OS X operating system do not have X11 support. You must download an X11 application and install it.

1. Using Spotlight, search for X11. The computer will respond with a message that X11 support can be downloaded from a web page.
   
2. OS X loads a web page.
   
3. Click the link on the web page to the XQuartz project.
   
4. Click the download link for the XQuartz disk image. the XQuartz disk image will be downloaded to your computer, and launched. Double click the XQuartz install package.
   
5. The XQuartz installation will begin. Click Continue.
   
6. Read the important information, then click Continue.
   
7. Read the license, then click Continue.
   
8. Agree to the license.
   
9. Install for all users of the computer. Click Continue.
   
10. Accept the default location. Click Install.
    
11. Watch the application install.
    
12. I missed the “successful installation” screen. But after that, XQuartz prompts you to log out and log back in.
    

Using XQuartz

Use Spotlight to find XQuartz. Launch the application.

1. XQuartz will open a terminal. You must either launch a local X11 application, or, as in this case, connect to a remote computer and launch a remote application.
   
2. Enter the connection string. In this example, we are connecting to dirac.chem.wsu.edu with the account username and specifying that we want to receive X11 traffic. Because this is the first time we have connected to dirac from this computer, X11 prompts us to accept the key of the remote computer. Enter yes.
   
3. The key is stored. Enter the password for the account.
   
4. The remote computer is ready to accept commands. Enter gv & to launch GaussView.
   
5. The remote application will be displayed on your desktop. When you are done, exit the application, then enter exit at the terminal.