You don't know? Have never heard of them? It is not surprising. Even though they are all candidates for the president of the United States the press does not inform the public of that.
This is a clear example of the consequences of framing a discussion. There are endless hours of coverage of the U.S. presidential race but it is almost all within the frame of the two main party candidates and vice-presidential candidates. Even coverage of better known independent candidates is very rare. When was the last coverage of RalphNader you saw?
All of this is part of the Tweedle Dee, Tweedle Dum expensive circus that constitutes much of western democracy nowadays.
It really matters very little whether Dee or Dum are elected. The two major parties both are tied into the system in a manner that makes any radical change impossible. What one has is product differentiation in the sales pitch and the creation of illusions about what each product will do to change things for the better. You can't get your money back. You just have to wait for the next election when you can change the product for a different one very much the same. Of course if you have lots of money you can hire a lobbyist to help you out.
Bob Barr is candidate of the Libertarian Party. Gloria la Riva is candidate for the Party for Socialism and Liberation Brian Moore is candidate for the Socialist Party of the USA. Allan Keyes is an independent
There are many other candidates including Cynthia McKinney the Green Party Candidate.There is a list of the other candidates at this site.