alt Hacker News> WASM seems to exist mostly because Mozilla threw up over the original NaCL proposal (which IMO was quite elegant). They said it wasn't 'webby', a quality they never managed to define IMO.
No, Mozilla's concerns at the time were very concrete and clear:
- NaCl was not portable - it shipped native binaries for each architecture.
- PNaCl (Portable Native Client, which came later) fixed that, but it only ran out of process, making it depend on PPAPI, an entirely new set of APIs for browsers to implement.
Wasm was designed to be PNaCl - a portable bytecode designed to be efficiently compiled - but able to run in-process, calling existing Web APIs through JS.
I don't think their concerns were concrete or clear. What does "portable" mean? There are computers out there that can't support the existing feature set of HTML5, e.g. because they lack a GPU. But WebGPU and WebGL are a part of the web's feature set. There's lots of stuff like that in the web platform. It's easy to write HTML that is nearly useless on mobile devices, it's actually the default state. You have to do extra work to ensure a web page is portable even just with basic HTML to mobile. So we can't truly say the web is always "portable" to every imaginable device.
And was NPAPI not a part of the web, and a key part of its early success? Was ActiveX not a part of the web? I think they both were.
So the idea of portability is not and never has been a requirement for something to be "the web". There have been non-portable web pages for the entire history of the web. The sky didn't fall.
The idea that everything must target an abstract machine whether the authors want that or not is clearly key to Mozilla's idea of "webbyness", but there's no historical precedent for this, which is why NaCL didn't insist on it.