Absolutely agree, Max and PD are great, but not super relevant to this discussion.
I've been combing through the Community Library trying to identify objects that would be useful for Midi effects. Really curious to hear what other objects folks use for this purpose. Here is what I've found so far:
cpwitz/midi: arpeggiator, paraphonic
jaffa/midi: Make Note
rbrt/midi/in: Monitor, keyb zone i, table store FULL, table toggle, table send note, table send vel
sss/midi: CC Zoom, Arpmidi, arpeggio, arepeggio2, clkIn, clkout, midichordIN, midichordOUT, rndmidinotes