unjoin is similar to unpack but it does not require (or allow) type arguments, it lets you group elements using the outsize attribute, and it passes any additional elements out the right outlet. It takes one argument which determines the number of outlets.
The @outsize attribute makes it easy to pass out chunks of larger lists without having to unpack and repack them.
Another feature of unjoin is that it doesn't care about types, so it can unpack lists of varying types without converting the output:
(please list things that you believe to be errors or omissions from the existing refpage)