Book excerpt: Visual languages have long been a pursuit of effective communication between human and machine. With rapid advances of the Internet and Web technology, human-human communication through the Web or electronic mobile devices is becoming more and more prevalent. Visual Languages and Applications is a comprehensive introduction to diagrammatical visual languages. This book discusses what visual programming languages are, and how such languages and their underlying foundations can be usefully applied to other fields in computer science. It also covers a broad range of contents from the underlying theory of graph grammars to the applications in various domains. Pointers to related topics and further readings are provided as well. Visual Languages and Applications is designed as a secondary text book for upper-undergraduate-level students and graduate-level students in computer science and engineering. This volume is also suitable for practitioners and researchers in industry as a professional book.