The Monkey Programming Language

The first book in the Monkey Canon defines the syntax of Monkey and describes its implementation as a tree-walking interpreter with the following features:

The Lost Chapter: A Macro System For Monkey was published in 2017 as a free (to read online or download) addition to Writing An Interpreter In Go. This book is the sequel to Writing An Interpreter In Go and while it does not change its syntax and does not add any features, it changes the implementation of Monkey from a tree-walking interpreter into a bytecode compiler and virtual machine. A full Monkey implementation of the bytecode compiler and VM from Writing A Compiler In Go in C# A fully working interpreter for the Monkey programming language as known from the book Writing an Interpreter in Go, written in Dart.

Source: monkeylang.org