Why would wasm replace containers? If you're going to run a binary why not just compile it for the local system?

We've always had 'compile once, run anywhere' but there's always been caveats and gotchas.

wasm targets the wasm runtime Virtual Machine (ie: a JavaScript VM). Offering fine grained isolation compared to virtualizing the whole operating system.

You could say the same thing for anything that targets JVM or CLR, and they're far more mature than any JS runtime.

Or even Lua, which is trivial to sandbox.

Something still compiles a WASM binary for the local system. Possibly, being able to optimize the WASM without recompiling it from source might be a win? Not needing separate binaries for ARM and x86 is nice, so it should run on a Mac more easily. Also, it runs on an edge server or in a browser, even on a phone, if you care about that.

I don’t think it will replace Docker files since they let you package up such a wide variety of existing server software and WASM is more limited. But if your software does compile to WASM then maybe you don’t care about that.

I think of WASM more like a plugin format, but I expect there will be a lot of engineering effort put into optimizing it, like happened with V8 for JavaScript. Not all web standards win, but betting against one that’s well-established and has a lot of support seems like a mistake.

For serverless (as in AWS-lambda-like) I agree. In that usecase WASM provides a better security barrier than containers, with faster cold-start time (which is really important for the scaling promise of these services).

For the stuff people run on their Kubernetes clusters I have more mixed expectations. Containers are more universal, but I can totally see a microservice architecture running as a lot of WASM runtimes with a handful of containers.

Particularly in the case of Amazon lambdas, those are running in VMS already (firecracker). Why wouldn't you skip the VM and use a static binary from rust instead?