The protocol itself is really only language-specific to a similar extent that JSON is language-specific. Which you can totally argue it is, but also people have

The protocol itself is really only language-specific to a similar extent that JSON is language-specific. Which you can totally argue it is, but also people have figured out how to use it in lots of languages other than JavaScript. I think Cap'n Web could work pretty well in Python and other dynamically-typed languages. Statically-typed would be a bit trickier (again, in the same sense that they are harder to use JSON in), but the answer there might just be to bridge to Cap'n Proto...