"The Chrome extension API was designed to work well with process separation and we are taking inspiration from it and copying functionality where it makes sense

"The Chrome extension API was designed to work well with process separation and we are taking inspiration from it and copying functionality where it makes sense. However, there will be differences, and the goal of WebExtensions is not to copy Chrome or allow Chrome extensions to run unmodified in Firefox, but to simplify cross-browser development by providing commonly-supported methods and interfaces. We won't implement all of Chrome's APIs, and Chrome is unlikely to implement some of the APIs we add. Imagine the APIs as a Venn diagram. In the middle are cross-browser APIs for content scripts, tabs, and windows. In the Firefox side are APIs for toolbars and other UI elements. On the Chrome side are APIs for Google's cloud services." Reading that made me extremely happy! I'm glad to see cross compatibility is still a goal for browsers.