The Sailfish browser is using Firefox rendering core BTW, so you might have used it elsewhere. ;-)
I don’t have any first-hand experience but from the comment that linked that blog, and the site itself, it’s not clear whether the browser engine has been updated since…
1. https://www.flypig.co.uk/?to=gecko&list_id=975&list=gecko
This is also why you see Chome being used as a core in all kinds of applications and frameworks - AFAIK it has the necessary API for this.