I'm sorry, but from the blog article it's not completely clear what this is. I knew a major rewrite was going to be required with Gecko and XUL being abandoned

I'm sorry, but from the blog article it's not completely clear what this is. I knew a major rewrite was going to be required with Gecko and XUL being abandoned by Mozilla: is this a step in that direction? Or just a stopgap measure while still relying on legacy code?