University of Victoria (Canada)
The U Vic Writer's Guide: Literary Term: Tragedy
The University of Victoria's English department gives a comprehensive definition of tragedy.
TheatreHistory.com
Theatre history.com: Sophocles and His Tragedies
This site provides a complete biography of Sophocles reprinted from a drama history book. Includes his innovations in ancient theater and his achievements as an artist.
Blackdog Media
Classic Reader: Hamlet by William Shakespeare
This is the full text of the five-act tragic play Hamlet by William Shakespeare including a list of characters.