[dahfizz]

Cross platform is in no way new. There are already plenty of ways for native devs to target multiple platforms at once if that's required.

[morgancmartin]

But are any of those ways both at the assembly level (speed) and decoupled from the runtime (space)?

My takeaway from WASI is that it would allow for a single universal runtime with near-native execution. The near-native aspect being what other universal runtimes like the JVM and CLR lack due to their bundling of a GC and other non-essential features.