KMidiMon is part of the Drumstick collection (https://drumstick.sourceforge.io/). It is a MIDI monitor program by Pedro Lopez-Cabanillas which can also load, save, display and play back standard MIDI files. It's the best program of its kind IMHO, on Linux at least. Alas, it's not packaged by all distros, even if they ship the Drumstick library and some of the other tools in their official repositories. Thus we provide some packages here (just Fedora for now).