How to run PLAI code

Recently I am learning the interpretor so I start to read PLAI(Programing Languages: Application and interpretation). However, for a noob of functional language, such like Scheme, Racket,... it's really a difficult job to figure out how to compile and execute code. Fortunately, after multiple tries and google, I find the answer.

Firstly, you need to install  DrRacket.

After you install DrRacket, open it. Go to File -> Install .plt File..., and in the URL tab, enter http://cs.brown.edu/courses/cs173/2012/lang/plai-typed-2013-04-29.plt or http://cs.brown.edu/courses/cs173/2012/lang/plai-typed-2012-12-02.plt. Then click Ok, a window will pop up with installation progress. When it's done, the Close button will be available. Refer to this link.

So here we are. you can write your plai code with #lang plai-typed on top of DrRacket.