I am currently reading http://hackage.haskell.org/packages/archive/containers/latest/doc/html/Data-Set.html#t:Set
What does following detail convey (to an absolute haskell beginner)?
Portability: portable (Which other are portability value?)
Stability: provisional (Which other are stability value?)
Maintainer: libraries@haskell.org
Safe Haskell: Safe (Is there something unsafe?)