Whether to use Sibelius or Musescore for "Simplified Notation" capability
I've been very interested in this alternative notation system for a while: http://www.simplifiedmusicnotation.org/
However, the website here is only offering a music notation plugin for Sibelius. I'm not even sure if they've heard of musescore. I'm completely stuck on what to do so I'm looking for advice. There's several possibilities:
1. I could purchase Sibelius and grab the plugin.
2. I could keep musescore and try to create my own plugin through the help of the musescore community.
3. I could ask the simplified notation folks to make a musescore plugin.
Option 1 would be the fast, legally-sound, and guaranteed to get me working on this new notation system. However, it would not be as cheap as just keeping Musescore, and I'm worried that Sibelius won't have an interface as intuitiveas that of Musescore. Everyone champions Musescore's interface as "that thing it does really well" and I love being able to modify the shortcuts to fit my needs. Is Sibelius modifiable, too?
Meanwhile, it seems really attractive to just lurk around the musescore community until I can figure out how to make the plugin myself (option 2). I'd save loads of cash and the plugin hardly seems like a dramatic project. I also know there's already similar plugins made for musescore. HOWEVER, I'm not sure if it would be legal. I can't quite figure out definitely what this license agreement implies: http://www.simplifiedmusicnotation.org/licence.doc FWIW: I live in the US and they live in the UK
And finally, I MIGHT save cash and legal trouble by asking the simplified notation folks to make a musescore plugin (option 3), but there's no guarantee they'll do it. It could take months or years before they investigate musescore, develop the product (which could mean hiring developers), and get it licensed.
Thank you all for your help, but lets please not debate the merits of the notation system itself (been there, done that, I've made up my mind).
Be aware that I'm currently leaning towards the Sibelius option if its interface can be as good as Musescore's.