Undergraduate students in computer science and computer engineers generally have a practical orientation: they study computing because they love programming and perform well in it. The book is primarily aimed at this core group of students.

The level of presentation does not require any knowledge of computer architecture, operating systems, formal languages, automata theory, mathematical logic, or inductive proof techniques. The main goal of a course that deals with the concepts of programming languages is to help the student understand programming languages at an unusual level of abstraction.

To achieve this goal, the book includes many exercises and examples of “real” programming, in order to encourage students whose interest in programming is primarily practical. It does not assume a high level of mathematical maturity on the part of the reader. It is designed to guide students to mentally process the abstract concepts of programming languages, starting from simple programming exercises.

The chapters of the book are divided into two categories: practical and philosophical in nature. The former are standalone “alphabets” for three programming languages from different families: ML, Java, and Prolog. The philosophical chapters present the theoretical side: the fundamental principles of programming languages. These chapters alternate with the practical chapters, in a sequence that facilitates the presentation of theoretical issues, so that their connection to programming practice is as clear as possible.