To be clear, Rust has also had support for asm.js and wasm via emscripten for quite a while. We're very enthusiastic about the new LLVM backend though, as it allows for significantly more control, including file size.

> (you cannot do that in WASM yet AFAIK)

wasm can do anything JS can by calling out to JS. What people mean when they ask for "DOM support in WASM" is to have it be direct, skipping the need for the JS call.

https://crates.io/crates/stdweb is an example of using WASM to manipulate the DOM through JS in Rust today.