Export to XML

[nitram45]

Dear LilyPond users,

I used to post questions on the LilyPond forums few years back when it was
possible to post and edit messages directly online (on nabble.com if I
recall correctly). But since it was closed, I didn't take the time to
subscribe to the mailing list and haven't try that way. I somehow managed
to find answers to my questions myself, but today I would need some advice.

I used to be an intense Finale then Sibelius user and I learnt LilyPond
back in 2017. Since then, it is my only tool to engrave my scores and I have
moved progressively my workflow on Linux. Hence I cannot (and doesn't want) to
go back on those proprietary software and it also changed my use of LilyPond (I
replaced frescobaldi by vim, I use a lot of separate folders for each
projects and program some Makefiles to link everything smoothly, ...). 

I received some good news recently. A big music publisher (Schott Music Group),
is interested in publishing some of my compositions I made for my piano students
and it should be released in a near future. I engraved my score with great care,
and as I said, using a Makefile and some unix architecture for that particular
project. However, as you might guess, they want to engrave it with their own
editorial chart and within their music software (I am not sure of which one they
are using yet).

I proposed to send them my LilyPond files but I have been confirmed yesterday
that they cannot process those... They told me an XML file might help them
though. I looked if it was possible to export in XML but I read the result was
bad and LilyPond wasn't made for that task... So here's my question: what would
you suggest I could do to export my scores and help them prepare the album? 

Thanks for the advices!