I always wondered this, figured i would finally ask Why are there 2 Googles?... 2 Berkshire Hathaways?... And like 20 Royal Dutch Shells??? Ive seen others, but cant remember all of them
I've never really looked it up for any reason until you just asked. Seems like they're just different kinds of shares. In GOOG/GOOGL example, one has voting rights as a shareholder, the other does not. You can read more here, but I'll quote the whole article below: http://www.investopedia.com/articles/markets/052215/goog-or-googl-which-google-should-you-buy.asp
I would imagine most stocks with multiple listings are for the same reason. The only other one that comes to mind off the top of my head is UA/UAA other than the ones you listed.
Ahhhhh.... sneaky Google Kinda reminds me of what Justin Timberlake did in that Facebook movie Id assume all the other companies with multiple symbols have similar reasoning