How can I open VLC multiple times?

From the Terminal window you can open multiple instances of any application by doing:

% open -n /Applications/SampleApp.app/

In this command SampleApp.app is the application bundle in the /Applications folder (see http://www.mactipsandtricks.com/articles/Wiley_HT_appBundles.lasso for a slightly old intro to what is inside an app bundle).

For VLC do the following:

% open -n /Applications/VLC.app

On OS X, the open command is used to open a file as it would be if you clicked on it via the GUI. You can try it on any file in your system to get a feel for how it works.

By using the -n option you get a new instance of the app even if one is already running. From the man page (i.e. man open at the Terminal) :

 -n  Open a new instance of the application(s) even if one is already running.

On the Mac, running multiple instances of VLC is not supported out of the box. You can follow the workaround given here,

http://wiki.videolan.org/How_to_play_multiple_instances_of_VLC