MPI, on FuzzBall TinyMUCKs, was developed by Revar Desmera, at The official name is Message Parsing Interpreter, but Revar says that it also stands for My Personal Insanity (after all, she had to have been insane to write 30,000 lines of C code to implement the damned thing.)

In FB, MPI has a much easier time dealing with property lists, which are trees of properties stored on objects within the database.