But you could do extreme programming. In fact, I had a college buddy I did pair programming with. We took a compiler writing class together and studied all that fancy stuff from the dragon book. Then of course the professor announced we would be implementing our own language, called PL/0. After thinking about it a while, we announced that we were going to do our project in BASIC. The professor looked at us like we were insane. Nobody else in the class was using BASIC. And you know what? Nobody else in the class finished their compiler either. We not only finished but added I/O extensions, and called it PL 0.5. That's rapid prototyping.