*Language name* is awesome!
Pyth, 37 bytes

.-Jjb.zpef!.-TJ+,kb+Rb._"pyth is awesome!


The source code is 41 bytes long. Try it online.

How it works

  Jjb.z                                      Save all user input in J.
                      ._"pyth is awesome!    Compute all prefixes that string:
                                               ["p", "py", ... ]
                   +Rb                       Append a linefeed to each prefix.
               +,kb                          Concatenate ["", "\n"] with the result.
         f                                   Filter the resulting array; for each T:
           .-TJ                                Perform bagwise difference between T
                                               and J (respects multiplicities).
         !                                     Take the logical NOT.
                                             Keep T if ! returned True, i.e., if J
                                             contains all of T's characters.
        e                                    Retrieve the last, longest match.
       p                                     Print it.
.-J                                          Remove its characters from J.
                                             (implicit) Print the result.