There’s a new upload of latest developments on OM for Linux at the usual places.
Main new feature is change from jack to portmidi for midi-event handling. The in-built fluidsynth is deprecated, and is no longer loaded by default. OM now instead relies on the user setting up something to connect to to make sound from midi-events. Hit the connection knob in the preferences->MIDI to connect to whatever synth you want to make sound with.
(Both the jack-midi client and the fluidsynth server are available in the code for those needing them.)
Issues: some of the ‘odder’ midi-messages aren’t yet supported, and if encountered (say, by playing a midifile containing one directly) will throw an error. A handler for these events will be set up soon.