The main difference is that gecko with the web apis to access hardware features provide a very nimble layer that makes quite easy to develop apps with JS that p

The main difference is that gecko with the web apis to access hardware features provide a very nimble layer that makes quite easy to develop apps with JS that previously could only be developer with Java or Obj-C/Swift. Its like phonegap without wrappers. Imagine if your web app could directly talk to hardware sensors, disk and phone features if the user gave it permission. The difference is that blink does not offer such APIs not this tight integration with the OS to the point where gecko is the OS. It used to be called "boot 2 gecko" for a reason