[mort96]

Sorry, I was responding to this:

> what's the point of taking machine code capable software, compiling it into WASM, and then compiling that back into machine code?

That's where the proliferation of instruction sets and instruction set versions is relevant. My comment wasn't trying to address the Java/.NET part of your question.

My response to "Why not Java bytecode" is here: https://news.ycombinator.com/item?id=32743910. I don't know enough about the design of the CLR to comment. In any case, neither Java bytecode nor CLR bytecode are proper open standards, so they seem like bad fits for the web unless Microsoft or Oracle wanted to lead an effort to turn them into web standards.

I don't have enough experience with compiler back-end theory to respond intelligently to what sort of challenges and benefits a stack-based IR represents, but I know that you can view a stack language as a language with arbitrarily many registers, which you can translate into SSA form, which lets you do efficient register allocation, so I imagine the stack-based nature might be okay? I agree that allowing unaligned memory access seems like an issue, but I suppose the alternative there is to have different alignment requirements per architecture, which hurts interoperability. I'd love to hear from WASM implementers whether this causes problems in practice or not.