[alquemist]

* Predictable performance.

* A wide ecosystem of mature language toolchains.

* Simplicity: JS implementation contain sophisticated JITs, which are harder to prove correct compared to a simple ASM translator.

* Portability: not tied to a specific HW architecture.

[jariel]

? Those are reasons to use JS not WASM.

"A wide ecosystem of mature language toolchains." - yes, for Javascript, not for WASM, which isn't deployed really anywhere in production and there aren't even best practices for it.

What language are devs going to even write these scripts in? That's not clear.

"Simplicity" - nothing is more 'simple' than JS, which is why it's used the world over.

"Portability" - again, nothing more portable than JS.

The reasons to use WASM are 'performance' along with 'black box' - but in most cases performance is not necessary and the black box for all intents and purposes exists with v8.

[alquemist]

I am not following WASM closely, but it appears to be deployed in all modern browsers: Chrome, Firefox, Safari, Edge. That counts as 'large scale production deployment', even if there aren't that many websites that take advantage of this capability (yet?). https://caniuse.com/wasm

[MaxBarraclough]

> "Simplicity" - nothing is more 'simple' than JS, which is why it's used the world over.

Not in terms of implementing the language.

[discreteevent]

Not in terms of using the language either. And the reason it is used the world over is because it was dictated to developers by browser makers. That's the single and only reason.

[MaxBarraclough]

I agree, but I'd still rank JavaScript as one of the more approachable major languages.

[x86_64Ubuntu]

How often does portability ever appear as a tie-breaker between to different languages?

[alquemist]

Rarely. Over a long enough time period though, the probability of a portability event nears 1, and the cost of such event is enormous. Right now there is a credible challenge for the x86 domination in the server, laptop and desktop markets raised by ARM, via AWS A1, Apple M1 and many others. Would be foolish to bootstrap an ecosystem locked-in to the loser, and we don't know the winner / loser over a 5-10 year timeframe.

[rattray]

For clarity, do you work at Shopify? These all sound like valid reasons, I'm just curious if they're the ones that motivated the Scripts team at Shopify.