Is Shakespeare Dead?

Last year in my English class my teacher showed us an article by Mark Twain, which question if Shakespeare wrote any of his own plays. Here is the URL   http://www.shakespeare-oxford.com/?p=119    Twain brings many interesting points to light, such as why was there no books in Shakespeare Will and as far as anyone can prove he received only one letter in his life.  And here is a BBC article with some different theories
http://www.bbcamerica.com/anglophenia/2011/10/did-shakespeare-really-write-his-plays-a-few-theories-examined/

-Greg