If you want to play around with my fork locally you need to install gopherjs from the latest master: go install github.com/gopherjs/gopherjs@master. It includes a couple of standard library fixes that make it work in an environment where wasm_exec.js is loaded. Same caveats apply, of course: it uses my quick-and-dirty fork of go-app, not something I would recommend for production use just yet.
Thanks @nevkontakte for https://github.com/nevkontakte/go-nats-app
This is a branch with that fork being applied.