real killer and root cause is that Chromium is well suited to being embedded, and Gecko is not. I don't think that's really the key problem since you don't hav

real killer and root cause is that Chromium is well suited to being embedded, and Gecko is not. I don't think that's really the key problem since you don't have to build a new browser out of FF by embedding Gecko. FF itself is a browser that was made out of another browser, much of the old core Mozilla technology is basically a cross-platform app-building framework with one of the 'apps' being a browser. Somewhat unobviously, this turned out not to be a great way to build a browser in the long run.