No,because your spec wouldnt suit everybody and you'll end up with 20 other specs. That's why there is not just 1 programming languages.Because silver bullets dont exist.
I meant a language that defines its syntax and functionality as a spec so it can be implemented in the same way in many languages so you can pick your favourite flavour and use it in as many languages as you want without surprises.
So given the template 'T' and template context 'C', you could always produce the exact same output regardless of whether you used javascript or python (assuming the libraries implemented the language based on the spec).
The spec doesn't mean it has to be a silver bullet, it will be a single bullet and there will be many bullets, but whatever bullet you pick, you can use it in more places.
I'd like to see a sane templating language that is based on a spec and it could be supported under different programming languages.