Forth Application Techniques was originally designed for use in programming classes, where students work through each chapter by doing the exercises on a computer. We at FORTH, Inc. have trained several thousand programmers to use Forth with versions of this book. Over the years we have adapted the content to reflect changes in common Forth usage and evolving computer and OS technology. We have also continually updated the problems to reflect the kinds of issues programmers face in real-world programming. This Sixth Edition is the latest, updated in 2019.