Scilab is a very powerful, free and open-source software package for scientific and technical computation, visualization and programming. It includes a large number of general purpose and specialized functions, using state of the art algorithms, for numerical computation. These functions are organized in libraries called toolboxes that cover areas such as simulation, optimization, image processing, control and signal processing. With easy to use high level programming language and huge library of functions, Scilab reduces considerably the burden of programming for scientific and technical applications. It can also be interactively used as a very powerful scientific calculator. Since Scilab is available free of cost to everyone across the globe and is continuously upgraded by a strong team of open source developers, it is suitable for all undergraduate students, researchers, professors and professionals in any field of Science and Engineering. Further, many commercial developers are also using it to reduce their project cost and has reported many successful applications.This book is written following several years of teaching the software to our students in introductory courses in numerical methods. The basic objective to write this book is to teach Scilab in a friendly, non-intimidating fashion, without any previous programming experience. Therefore, the book is written in simple language with many sample problems in mathematics, science, and engineering. Starting from the basic concepts, the book gradually builds advanced concepts, making it suitable for freshmen and professionals. The source codes of all the examples presented in this book can be downloaded from https://github.com/arvindrachna/Introduction_to_ScilabFor promoting outcome based learning, each chapter of the book starts with chapter objectives and lucidly introduces the basic concepts, with sample examples, to achieve those objectives. Each chapter concludes with a summary and a list of key terms to recapitulate the learned concepts. Finally, the chapter ends with exercise problems so as students can apply the concepts learned in the chapter.The book consists of seven chapters. The first chapter gives a focused introduction to Scilab and explains how one can install the software on ones machine. The second chapter introduces the core concepts of Scilab, a matrix based technical computing environment. This chapter also introduces how the software can be used in its interactive mode to solve scientific and technical problems. The third chapter introduces how to create and manipulate vectors and matrices in Scilab. It also introduces array and matrix operators. The fourth chapter explains how polynomials can be processed in Scilab. Polynomial operations, differentiation and integration are also introduced. The fifth chapter explains graphics capabilities of Scilab. Various 2D and 3D graphics functions are explained in this chapter. The sixth chapter is focused on the programming capabilities of the software. Various programming constructs are explained with examples. The last chapter explains basic numerical methods and how to create Scilab programs for them. This chapter helps students to apply the learned concepts to actual numerical method problems. The book ends with an appendix of commonly used Scilab commands and functions.Table of Contents1Introduction to Scilab2Basics of Scilab3Vectors and Matrices4Polynomials5Scilab Graphics6Programming in Scilab7Numerical Methods Using Scilab8Appendix I : Commonly Used Scilab Functions