Well, usually when you press Enter you can type something in...
And when you press Enter with worldbuilder.lua on, it asks you to type the name of the mod so that you can save it.
So, when you press Enter on worldbuilder.lua, it opens both chat and the save boxes.
And by pressing Enter the second time, it removes the chat box (sends the message typed in chat), and then you can type the name of the mod...
I don't remember if it was the other way around, but eh...
I just said it just in case. :v