To my knowledge, OCaml already has this feature to offer different syntaxes to
the users, varying from enhanced
[OCaml](http://camlp5.gforge.inria.fr/doc/htmlc/revsynt.html) to
[Scheme/List](http://camlp5.gforge.inria.fr/doc/htmlc/scheme.html) or even
[user
defined](https://forum.nim-lang.org/camlp5.gforge.inria.fr/doc/htmlc/redef.html).
Even in C, you can
#define begin {
#define end }
to switch to a Pascal-like syntax.
In fact, any language supporting macros allows a type of syntax variation. I'm
not sure this is really a vending feature, nor desirable. If any programmer is
able to favor a personal syntax style, how to you deal when they work on the
same source file?
I'm leaving in a bilingual country, and I've spent my afternoon today splitting
a bilingual document (you see, the kind with two columns, one in French and the
other one in English) because a person with disabilities was not able to read
it with her aural browser. Mixing languages in the same document is not always
a smart idea...
