What do you mean by "script"? There was a spelling reform in 1996/2006 which changed, obviously, the spelling rules (but not grammar or vocabulary).
There are also quite a number of cursive scripts (ways of writing, e.g. Sütterling) and printing typefaces (e.g. Fraktur), for a summary see http://de.wikipedia.org/wiki/Deutsche_Schrift
. Of course these are only a way of writing the letters, so the scripts/typefaces themselves don't change grammar rules etc. But then, they are typically associated with a certain period, which often had its own style, vocabulary, spelling, and turn of phrase, just as English has (think Shakespeare or the King James bible).