I like RSpec's new feature, RSpec Stories.
In the past, I saw Acceptance Test Cases written in plain text and the approach worked very well.
By the way, RSpec Stories is in English. And of course, all the programming languages use English for their keywords as far as I know. But I'm learning French now. And French speaking customers writing Stories in English doesn't seem to work well. And developers translating French to English introduces one more layer of indirection, which we want to avoid. I wonder if there is a solution to this problem. Maybe we can make a translator. It will be simple because it contains only RSpec stories keywords.