An experimental investigation into a multithreaded model (for UI and webpages) was investigated a few years ago (see https://bugzilla.mozilla.org/show_bug.cgi?i

An experimental investigation into a multithreaded model (for UI and webpages) was investigated a few years ago (see https://bugzilla.mozilla.org/show_bug.cgi?id=718121 https://bugzilla.mozilla.org/show_bug.cgi?id=718121 ), and I don't think it looked to be "much simpler". The major problem with moving to multiple processes is that JS running the UI has to be adapted to dealing with page JS that is "somewhere else". Because the JS execution model is based on a single thread, I don't think it would be so much easier to deal with JS on another thread than in another process. Requiring multiple JS runtimes would likely also increase memory usage even in a multithreaded model, though it does seem like it would be less than e10s.