A friend of mine dislikes composing music on the commercial software he owns (Si..us). The main reason is that he is into modern, avant-garde music and the notation on his current system is just not there yet or what's offered does not satisfy him. He is a professional music composer.
I have no idea about music composition. I really love LaTeX and would consider no other alternative. I am quite able with it and I am able at programming in general.
He asked me for helping him and I see I have two choices, either I experiment writing some plugin for his current commercial software I mentioned, which is uncharted waters for me plus only available on an OS I don't have, or ...
... using a TeX-based or TeX-like (free) music composition system, if available and doing all programming, templating etc. in this myself. Advantages: platform independent and free.
I can manage any installation challenge and possibly I can persuade him to free himself from the GUI for the sake of programmability and typesetting/engraving quality.
So, my question is:
Has anyone here had any experience with both the free and the commercial music-composition softwares and can give some advice whether it's wise to dump the commercial for the free without compromising typesetting quality which is my primary metric.
And also whether there will be lots and lots of symbol libraries for him to choose from?
Edit: I posted similar question on LilyPond user forum