from website: WebAssembly (abbreviated Wasm) is a binary instruction format for a stack-based virtual machine. Wasm is designed as a portable compilation target for programming languages, enabling deployment on the web for client and server applications.
asm.js
an extraordinarily optimizable, low-level subset of JavaScript
http://asmjs.org/
so, IMO WebAssembly is not a stripped down version of asm.js even if they sold it as that to js devs to foster adoption
Yes, you are correct. What I wanted to say is that webassembly is a continuation in that direction.
At the time asm.js was ideated the alternative were browser plugins like NaCl, Flash, or Java.
The problem with asm.js is that the requirement to be a subset of javascript meant that some optimizations were impossible. wasm is another step in that direction.
asm.js an extraordinarily optimizable, low-level subset of JavaScript http://asmjs.org/
so, IMO WebAssembly is not a stripped down version of asm.js even if they sold it as that to js devs to foster adoption