This is a 5-part tutorial on how to implement a programming language. It is intended for people with some programming experience, who want to know how their compiler, interpreter or virtual machine works. Hint: it's not magic.
There are many articles (even books!) on this topic. I'm writing mine with two purposes in mind:
The reader is expected to have basic-to-average programming knowledge, especially about objects, data structures and variable scope. Knowing some Javascript is necessary in order to understand the sample code.
Note: this tutorial is obsolete. You might want to take a look at the second edition: Your Very Own BASIC Interpreter.
Each part comes with a working Javascript implementation of the interpreter described until that point. The code is tested and believed to work in Opera 9.5+, Firefox 3, WebKit and Konqueror.
Alex Bolboacă has been kind enough to review parts of the tutorial.
Syntax highlighting of the code samples is powered by JUSH.