[marcosdumay]

My guess is that the resource protection of WASM is quite well made.

There are experimental or hobbyist VMs with great resource protection but that didn't receive a lot of attention, so they have all kinds of sharp edges. And there are mainstream VMs that all completely suck at resource protection even when it's one of the main goals of the project.

On the middle, with a good enough to be useful amount of protection, and receiving attention enough to be usable, there is basically only WASM.

I imagine there is an amount of javascript-like "I want whatever I have on the browser, so I'll have to learn less stuff" happening too. But I don't think it's as relevant, because there is much less to learn when picking a VM.

[amelius]

Ok, how well are things like multithreading currently supported on WASM? How about shared memory (e.g. for efficient immutable structural sharing)? And does WASM support special instructions (memory barrier instructions come to mind) that allows one to implement (say) a garbage collected runtime on top of it?

[marcosdumay]

The fact that it has a niche doesn't mean it's good for everything.