> From section 3.3.1 in the manual: https://www.gnu.org/software/mes/manual/mes.html
>
> "Setting MES to a mes-compatible Scheme will run mescc using that"
>
> What is a "mes-compatible Scheme"? That term does not appear again in the page.

I'm not sure but I'd say that applies to Mes and Guile at the moment.