[vincentriemer]

FWIW I believe that web worker adoption is more limited by tooling/knowledge than APIs. Web developers haven't thought about thread safety for decades (at least for those who have been around for that long) so it's more of a mental leap for web developers to think in terms of multiple threads.

I had some promising (at the very least interesting) results with react-native-dom which runs all of React's reconciliation & your own business logic in a web worker: https://rndom-movie-demo.now.sh. I'll fully admit there's a lot more exploration/experimentation left to be done in this space though.

[acjohnson55]

One correction: I don't think thread safety is the issue at all. First of all, existing Javascript may not have parallelism in user code, but it does have concurrency. This means you absolutely have to deal with race conditions and resource sharing. Secondly, web workers can't access the mutable state in parallel, because they can only share data via message passing of copied data. This is what prevents thread safety from being a concern, while still enabling parallelism.