[bholley]

The purpose of RLBox is to add an extra layer of component-level isolation on top of Firefox's process-based site-level isolation. The reduced overhead is relative to the hypothetical scenario in which we performed the component-level isolation with processes (rather than WebAssembly).

[rajanaccros]

Ohh I see. Not a replacement for process based site level isolation. I just wasn't wrapping my head around that. Makes much more sense now. Thanks for the explanation.

[majkinetor]

However, without removing processes it will still be as slow as today, which I really hope browsers will do.

[ekr____]

I think a more likely way to think about it is that this allows us to sandbox things that would otherwise would not be sandboxable. For a variety of reasons, it's probably not practical to remove the existing process sandboxes.