After working intensively on a bigger project, I hit the wall with a problem that required some simple recursive calls: unfortunately, that part had to be implemented in Max alone.
I came to muse on whether there were no easy way to enable functional style recursive calls in Max, and came up with three small abstractions that allows you to define and call a function (def, call and return). I've put them up with a sample factorial implementation.
There seem to be some problems with stack space (mostly in Overdrive mode), but they seem to work quite efficiently otherwise.
What do you think? Maybe this could be expanded into some set of functional utilities.