(Sorry for crossposting, but according to the statistics there are many people who are in only one list and I want to hear the opinion of both devs and users)
If would like you to have a look at my initial thoughts about live-midi with notation, or the developing of a notation-based midi sequencer (for Denemo). It would be interesting to hear your thoughts, additions or comments (besides "You made a spelling/grammatical error").
Of course if you are interested in this or other things your help would be welcome, we are always searching for help @ Denemo. Denemo is a Open Source Music Notation Editor, based on lilypond and written in C. (And I know no better one :)