# AcknowledgementsAcknowledgements

This text began as my sabbatical project in the winter semester of 2012, during which I wrote the preponderance of the materials for the first four chapters. For the sabbatical leave, I am indebted to Grand Valley State University for its support of the project and the time to write, as well as to my colleagues in the Department of Mathematics and the College of Liberal Arts and Sciences for their endorsement of the project as a valuable undertaking.

The beautiful full-color .eps graphics in the text are only possible because of David Austin of GVSU and Bill Casselman of the University of British Columbia. Building on their collective longstanding efforts to develop tools for high quality mathematical graphics, David wrote a library of Python routines that build on Bill's PiScript program, and David's routines are so easy to use that even I could generate graphics like the professionals that he and Bill are. I am deeply grateful to them both.

For the print-on-demand version of the 2016 text, I am thankful for the support of Lon Mitchell and Orthogonal Publishing L3C. For the first print edition of the text, Lon provided considerable guidance on LaTeX and related typesetting issues, and volunteered his time throughout the production process. I met Lon at a special session devoted to open textbooks at the 2014 Joint Mathematics Meetings; I am grateful as well to the organizers of that session and subsequent ones who are part of a growing community of mathematicians committed to free and open texts. You can start to learn more about this work at the American Institute of Mathematics' open textbook site.

The current .html version of the text is possible only because of the amazing work of Rob Beezer and his development of the original Mathbook XML, soon to be known as PreTeXt. My ability to take advantage of Rob's work is largely due to the support of the American Institute of Mathematics, which funded me for a weeklong workshop in Mathbook XML in San Jose, CA, in April 2016. David Farmer's conversion script saved me hundreds of hours of work by taking my original LaTeX source and converting it to MBX. Alex Jordan of Portland Community College has also been a tremendous help, and it is through Alex's fantastic work that live WeBWorK exercises are not only possible, but also included in the 2017 version. Alex has also contributed substantially to the .pdf version of the 2017 text.

Over my more than 15 years at GVSU, many of my colleagues have shared with me ideas and resources for teaching calculus. I am particularly indebted to David Austin, Will Dickinson, Paul Fishback, Jon Hodge, and Steve Schlicker for their contributions that improved my teaching of and thinking about calculus, including materials that I have modified and used over many different semesters with students. Parts of these ideas can be found throughout this text. In addition, Will Dickinson and Steve Schlicker provided me access to a large number of their electronic notes and activities from teaching of differential and integral calculus, and those ideas and materials have similarly impacted my work and writing in positive ways, with some of their problems and approaches finding parallel presentation here.

Shelly Smith of GVSU and Matt Delong of Taylor University both provided extensive comments on the first few chapters of early drafts, feedback that was immensely helpful in improving the text. As more and more people use the text, I am grateful to everyone who reads, edits, and uses this book, and hence contributes to its improvement through ongoing discussion.

Finally, I am grateful for all that my students have taught me over the years. Their responses and feedback have helped to shape me as a teacher, and I appreciate their willingness to wholeheartedly engage in the activities and approaches I've tried in class, to let me know how those affect their learning, and to help me learn and grow as an instructor. Early on, they provided useful editorial feedback on this text.

Any and all remaining errors or inconsistencies are mine. I will gladly take reader and user feedback to correct them, along with other suggestions to improve the text.