One thing I've never really seen a lot of in many ATLs is how language develops in an alternate world. It stands to reason that, if for example, the Normans never invaded England, then English would be very different (or, "More like the Dutch of our world," as L. Sprague de Camp's character once put it in "Aristotle and the Gun").
So, starting with perhaps Rome losing the Punic Wars, how might have the later Romance languages have developed after several centuries of greater Greek and later Germanic (I think) influences?