MIDI hotplug support for MacOSX via native CoreMIDI backend is almost ready.
Main advantages:

  • no need to restart Pd if new MIDI device has been plugged (the problem can't be solved while using PortMidi backed)
  • support virtual source and destination devices: "to PureData" and "from PureData" for connection with other software
  • supports SysEx messages up to 65536 bytes
  • supports simultaneous intermixed SysEx output to several devices (unlike PortMidi backend)
  • fixed bug when Midi device name contains curly braces

Here's develop test build with supported MIDI hotplug on MacOSX: