This is the Jack Compiler for all your Jack code!
This program takes code written in the Jack language and translates it into virtual machine instructions, to be further compiled down to machine code to run on the operating system and hardware built during nand2tetris.
Jack is a high-level object-oriented language modeled after Java. It was created for the nand2tetris project to demonstrate how high-level code is compiled into machine code run by a computer's hardware in a hands-on way.
You shouldn't, actually! It's meant for learning and demonstrating the principles behind the compilation of a real programming language. Once you've learned how compilation works, the book encourages you to dive into real compilers like LLVM! That's what I've done and I greatly recommend it.
(Coming soon...)