Actually on Windows we have come full circle as those CLR ideas, which were originally thought for COM Runtime, have been brought back into COM as UWP.
IBM mainframes also follow the multi-language environment philosophy.
Yup I mentioned Microsoft COM (which Mozilla's defunct XPCOM was modelled after). Shared libraries and binary interfaces, rather than C header files.
Come to think of it I'd like to see a postmortem on XPCOM.
Chrome uses apparently uses more of a build time tool to generate interfaces in both C++ and JavaScript.
"they should focus on interoperating with other languages (as in the Unix philosophy)."
Maybe instead follow the OpenVMS philosophy where they standardized the calling conventions to support multi-language development.
http://h41379.www4.hpe.com/doc/82final/5973/5973pro.html#int...
Microsoft's CLR followed that path in the VM space. Got similarly good results. Tools like Racket and mbase do with DSL's where they share underlying LISP-like language to avoid problems with DSL's own weaknesses.