The title writer might be doing the project a disservice by using the term "formal" to describe it, given that the project talks a lot about "specs". I mistook it to imply something about formal specification.
My quick understanding is that isn't really trying to utilize any formal specification but is instead trying to more-clearly map the relationship between, say, an individual human-language requirement you have of your application, and the code which implements that requirement.
My quick understanding is that isn't really trying to utilize any formal specification but is instead trying to more-clearly map the relationship between, say, an individual human-language requirement you have of your application, and the code which implements that requirement.