> As I understand it, it's not even really possible today to make WebAssembly do anything meaningful in the browser without trampolining back out to JavaScript

> As I understand it, it's not even really possible today to make WebAssembly do anything meaningful in the browser without trampolining back out to JavaScript anyway, which seems like a remarkable missed opportunity. It was always the goal for WebAssembly code living in the browser to have some form of object model/DOM integration, and interaction with JavaScript objects. What form it would take exactly wasn't clear. But that was never a goal for the original 1.0 specification (MVP), and not even in spec for the current 2.0 draft -- which mostly add a bunch more useful instructions and features, but nothing earth shattering. The reality is that whatever solution gets accepted has to be supported and continue working for what is effectively ~infinite time, in multiple major browser engines. For custom runtimes it's sort of "whatever", but webpages can live forever so it's taking a lot of time to get right. But there was clearly a lot of value to be had without that, hence 1.0 was the "MVP."