Aria Maestosa is an open-source (GPL) midi tracker/editor. It lets you compose, edit and play midi files with a few clicks in a user-friendly interface offering score, keyboard, guitar, drum and controller views
What's new in Aria Maestosa
Encoding issue when exporting to midi on windows
Track name encoding when exporting to MIDI
Song name and copyright encoding when exporting to MIDI
Well, I have not more to say than 6 years ago. ;-)
But I haven't found a better and simple alternative.
I take back one star because, thinking about it, I wouldn't even try editing a midifile with it — I wish it was the copy of what Cubase was on Atari thirty years ago ;-) — but to have a fast idea of what's inside a midifile before importing it in a bigger software, it's ok.