An overview of programming languages: assembly language, procedural languages, and functional languages. This book is intended for readers who have a good foundation in writing code in some high level language (C++ or Java would be fine). The goal is to introduce compiler and interpreter concepts and implement various languages within the four parts of the text. - Part I focuses on assembly language and builds an interpreter for KCODE code for the interpreter is implemented using C - Part II focuses on introducing procedural languages and builds a compiler for CALC code for the compiler is implemented using the Icon Programming Language (Unicon) - Part III builds on Part II to elaborate on specific topics within compiler construction and builds a compile for KIZE Icon Programming Language - Part IV focuses on functional programming and ultimately builds an interpreter for SKEME Icon Programming Language The reader may implement his or his own version of the interpreters/compilers. The book attempts to walk them through the various steps and share the author's experiences. The readers are free to choose a high level language for their own use. But I highly recommend a language with a straight-forward syntax and powerful string manipulation tools. That is my reason for my personal choice of Icon for the majority of the book.