This is the shareware version of MidiLang.
A registered version is available for 35$.
With it, the maximum number of MPL instructions is set to 800, no more "please register" screen.
and you will find included in the registered package of MidiLang :
MidiLoop : MidiLoop is a mini-MidiLang specialized in echos. Very easy to use.
MplDebug : a simple but useful debugger of MPL files to trace MPL behaviour.

Please see : order.txt to get details about how to register.