Congrats on a a really well presented site. Just offering what I think is a minor correction:
This sentence from the Flyweight pattern description is confusing:
"The flyweight maintains intrinsic state (state that is shared among the
large number of objects that we have created the flyweight for) and
provides methods to manipulate external state (State that vary from
object to object and is not common among the objects we have created the
Should the first parenthetic statement instead read: " intrinsic state (state that is not shared among the
large number of objects..." ?