One of the hidden gems (in my mind, but then I’m biased) in the Microsoft “Oslo” SDK that went public at PDC is the “M Script Mode” in Intellipad which we affectionately know as MrEpl.
MrEpl is a REPL processor for the MSchema language and is a great way to play around with M and learn about it.
I have recorded a screen cast of some adventuring through MrEpl and it is posted on the Oslo dev center here: http://wm.microsoft.com/ms/msdn/oslo/MrEplWalkthrough.wmv
For those who just want to play, make sure you have the Oslo SDK installed, then run “Intellipad (With Samples)”.
– Once in Intellipad type “Ctrl-/” to get to the minibuffer.
– There type "SetMode(‘MScriptMode’)”
You’re now in MrEpl. Feel free to type an M expression: 1 + 1