It is pretty much not like anything else around (although it has been already compared to "brainfuck") and the reason for its creation will be made apparent at a later time.
Rather than describe the whole thing in detail I'll just show a couple of examples:
!hello
would result in the output:
a more sophisticated example is as follows:
@reverse=?x!final_>x,y_
@test=@x=?_@y=_@z=_?x!assign_!reverse
!test
which would result in the output:
and if you then did this:
you'd see this: