I developed the most feature-rich editor for Lilypond (as a plugin for jEdit). It had midi, virtual keyboard, integrated pdf viewer, templates, snippets, autoco

I developed the most feature-rich editor for Lilypond (as a plugin for jEdit). It had midi, virtual keyboard, integrated pdf viewer, templates, snippets, autocomplete, lots of cool stuff. I also built an on-the-fly syntax checker. However, Lilypond development gradually turned to a direction that made it impossible to create a useful syntax checker. As you could actually change the language itself in your source file, by actually changing the enormous amount of Scheme code that provided the Lilypond features. So at the end one couldn't provide reliable edit time autocomplete or error checking, because they needed to actually run the Lilypond interpreter. So I gave up and switched to MuseScore. I even got time to create scores and learn my instruments :)