Some years ago I started to write a Midi software, MidiYodi, in order to quickly analyze the content of MIDI files. Apart from that is is very fast to open any MIDI file where each track and event could be viewed I also included a MIDI file browser that examines and list the contencts of all MIDI files in a selected folder (directory). Very handy, without even having to open them!
Over the years MidiYodi has been updated with editing capabilities in terms of program change, note editing, track editing, in fact editing any individual MIDI event, MIDI file type conversion and much more so I would say that it now qualifies very well as both a MIDI examiner and a MIDI editor, and ofcourse it includes playback as well.
Written in Java so it is available on Windows, Mac and Unix.
You can find little MidiYodi here: