Noteur

Noteur is a general purpose midi file editor that is focussed upon the use by people who work with midi files for mechanical instruments.

It is a piano roll based editor. The user can open a gamma file, that is a description of the instrument he or she is working for.
Noteur then 'knows' the instrument and supports the user with a series of handy functions. One of the strong features is the embedded programming language MPL.