What are the linguistic/framework 'limits' of copilot?

Does AI support (or otherwise try to support) all the world’s programming languages? (Even dinosaurs like COBOL or FORTRAN)

What about some niche frameworks? And such a sub-hair question - has anyone tried writing in any esoteric language?

From the website “Trained on billions of lines of public code” this should also cover sone rare languages.

Besides that, the website also says ”GitHub Copilot works with a broad set of frameworks and languages. The technical preview does especially well for Python, JavaScript, TypeScript, Ruby, and Go, but it understands dozens of languages and can help you find your way around almost anything.“ and of course you can try the Copilot’s AI.

But for the first start the foucs will be on productivity and therefore not directly on some esoteric languages.