There are many stories that were written for the screen, but could not be told through that medium for various reasons. Whether the scripts were unshootable, spec scripts, early versions of aired episodes, or pushed back for a later season that never came, the Battlestar Wiki and its redoubtable contributors have found various scripts that were never produced.
Of course, their canonicy is debatable, but these are looks at stories that may have been to shows that have long since ended. Take a look.