The project are based on the book crafting interpreters who implements a language who has a dynamic typing system and a lot of basic features to see how it works in practice.
After you clone the repository, start hacking arround lox.js with node:
node lox.js
This command jump into the REPL of the language with essential features to see the language in action. For a more deeply interaction you can run scripts passing the path of file.
node lox.js examples/fizz-buzz.lox
With this in mind you can go beyond looking into the book.
All contributions are welcome, to give more power to the language.