The fifth edition is an evolutionary improvement over the fourth and earlier editions. See the updated Preface to the First Edition (overleaf) for more detailed information on the book's purpose and organization. The principal changes in this edition are:

• A new chapter (16) has been added on cam-driven and servo-driven linkages based on the author's recent consulting experience that indicates increased use of servomotors to drive mechanisms in machinery.
• Over 50 new problem assignments have been added. All of the problem figures are included as PDF files on the DVD so that students can easily print hard copies on which to work the solutions.
• Several of the author-written programs that come with the book have been completely rewritten to improve their interface and usability, and they are now compatible with the latest operating systems and computers. The programs Fourbar, Fivebar, Sixbar, and Slider have been combined in a new program called Linkages that does everything those programs collectively did and has some new features added. Program Dynacam also has been completely rewritten and is much improved. Programs Engine and Matrix are unchanged. These computer programs undergo frequent revision to add features and enhancements. Professors who adopt the book for a course may register to download the latest student versions of these programs from: http://www.designofmachinery.com/registered/professor.html.
• The Working Model program that was provided with earlier editions was not a full-featured version of the program. It did not allow the user to save or print a model. The version of Working Model available with this text is a fully capable version but is provided only by means of a one-time download from a website and will run for one year from the time of installation. A password is provided with this text to enable its download.
• Many small improvements have been made to the discussion of a variety of topics in many chapters, based largely on user feedback, and all known errors have been corrected.
• The extensive DVD content that was introduced in the Fourth Edition is included with the Fifth Edition as well. These include:
• The entire Hrones and Nelson Atlas of Coupler Curves and the Zhang Atlas of Geared Fivebar Coupler Curves are provided as PDFs on the DVD.
• Eighteen instructional videos that provide several lecture/demonstration tutorials on subjects such as position synthesis, coupler curves and cognates, the Grashof condition, etc. Others show real machinery that uses linkages, cams and gears for such tasks as spring manufacture, bottle printing, and pick-and-place mechanisms for automated assembly.
• Wang's Mechanism Simulation in a Multimedia Environment that contains over 100 Working Model (WM) files based on the book's figures and 19 Matlab® models or kinematic analysis and animation is included.
• Videos of two "virtual laboratories" that replicate labs created by the author at WPI are provided. These include demonstrations of the machines and spreadsheet files of the acceleration and force data taken during the experiments. The intent is to allow students at other schools to do these exercises as virtual laboratories.