I considered Lambda and similar, but keeping LilyPond running as a server allows for lower latency, which is important given how long it takes for LilyPond to start up.
I don't think I'd be able to have the kind of live reloading I implemented here with Lambda.
Hacklily is great! Obviously doing fine with the HN burst! I may just point people to yours at some point.
For example VexFlow (http://www.vexflow.com/) or, even with music, abcjs (https://abcjs.net/). Both of those use their own language.
A cursory look at the lilypond docs makes it seem like the language is pretty simple and straightforward... although, the source code looks nuts. How hard do you think a JS parser/vm for it would be?
Edit: been looking at some large lily projects from mutopiaproject linked below. Oof. There's more there than the docs let on. Still, would be a very interesting project...
To me learning through programming is very natural so I'm excited to try my hands on composing using this language. Didn't ever occur to me that the notation would be that simple. With same effort and time you put into learning say C++ could you become a proficient composer with this?
Making community features is a natural next step which might help with finding examples.
LilyPond has a bit of a steep learning curve, but you can absolutely use it professionally. http://www.mutopiaproject.org/ shows what LilyPond can do. Personally, I find that I can be more productive with LilyPond than with Finale, and that the results look better.
I was never any good with Finale or Sibelius, so I feel like I'm unqualified to say whether Musescore is worth learning, but have been curious what an actual skilled Finale user thinks about it?
I use Frescobaldi ( http://frescobaldi.org ) for my Lilypond editing and find it pretty good.
I think if this had existed back then, the much-faster feedback loop would have helped me finish it. :)
Then I saw the play in the top bar :D
Pure awesomeness!