Note that the document seems to be from the spring of last year.

I think it is interesting that Parasail has no explicit pointers and only uses value semantics. This means that no garbage collection is needed: the storage associated with a variable is freed when the variable goes out of scope, or when the variables value is set to null (and yes, you must have a value of type Optional T in order to set it to null). I thought that having pure value-semantics would be too costly in a language, but apparently that kind of solution has its place after all.