"Rltool for Scilab" is a software tool for simulating linear systems designed for undergraduate control education. The features incorporated into this package are generally limited to what a student encounters in a first course on control systems. Every effort has been made to provide an easy to use graphical user interface and a powerful simulation environment. Rltool for Scilab aims to be as inexpensive as possible. It has zero cost, hidden or otherwise, making it an attractive choice for educational institutions with a low budget and for students who like a simple and free tool to play with control engineering concepts.