> I'm guessing HHVM only really powers the API, business logic, etc. So "only" everything except UI (which is run by the browser, not FB's servers), then. And

> I'm guessing HHVM only really powers the API, business logic, etc. So "only" everything except UI (which is run by the browser, not FB's servers), then. And that's only for browsers that use it at all, as they still need to render a lot of stuff from the servers both for speed and for people who turn off js or use older or limited browsers. And this is a weird thing to say anyway, nothing runs "on" react; both the framework(s) and the business logic run on something else.